Mt Victoria to Cobham Drive scoping study: …...Page i Technical Report - Transport June 2011...

Mt Victoria to Cobham Drive Scoping Study - Technical Report - Traffic and Transport Assessment and Evaluation

© NZ Transport Agency

www.nzta.govt.nz

2011

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Page i

Technical Report - Transport

June 2011

Record of amendment

Report reviewed by:

Name Position Signed/approved Date

D Turner Transport Lead/Deputy study lead 16 Dec 2010

C Purchas Study lead 23 Mar 2011

T Brennand Client Project Manager 23 Mar 2011

T Kelly External peer review 13 April 2011

W Stewart External peer review 18 April 2011

Report approved by:

Name Position Signed/approved Date

C Purchas Study lead 5 May 2011

Details of Revision

Amendment

number

Description of change Effective date Updated by

A Draft Issued for review 23 March

2011

GMN

B Revised following external peer review 5 May 2011 GMN

C Revised following edit 25 May 2011 GMN

D Revised with updated cost estimates 30 May 2011 GMN

Page i


May 2011

Contents

1 Introduction ......................................................................................................................................................................... 1

1.1 Background ..................................................................................................................................... 3

1.2 Project Objectives ........................................................................................................................... 4

1.3 Report purpose and structure ....................................................................................................... 6

2 Background information .............................................................................................................................................. 7

2.1 State Highway 1- Route description .............................................................................................. 7

2.2 Local roads ..................................................................................................................................... 9

2.3 General traffic characteristics ...................................................................................................... 10

2.4 Property access............................................................................................................................. 13

2.5 Public transport routes ................................................................................................................ 13

2.6 Walking and cycling ..................................................................................................................... 14

2.7 Safety assessment ........................................................................................................................ 17

2.8 Population growth ........................................................................................................................ 22

2.9 Employment growth ..................................................................................................................... 25

2.10 Wellington Airport growth ........................................................................................................... 26

2.11 Access to motor vehicles ............................................................................................................. 27

2.12 Travel to work .............................................................................................................................. 27

2.13 Kilbirnie growth node .................................................................................................................. 29

2.14 Adelaide Road growth node......................................................................................................... 30

2.15 Summary ....................................................................................................................................... 31

3 Issues and opportunities to be addressed ..................................................................................................... 33

3.1 Multi-modal use of the corridor ................................................................................................... 33

3.2 Local traffic movements and connectivity .................................................................................. 34

3.3 Intersection treatment ................................................................................................................. 36

3.4 State Highway alignment ............................................................................................................. 38

3.5 Pedestrian and cyclist options ..................................................................................................... 38

3.6 Public transport use of tunnels ................................................................................................... 40

3.7 Travel demand management ....................................................................................................... 40

4 Options identified .......................................................................................................................................................... 42

5 Transport evaluation framework and assessment of options ........................................................... 48

5.1 Description of transport-related evaluation criteria ................................................................... 48

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May 2011

5.2 Assessment against transport evaluation framework ................................................................. 49

5.3 Operational assessment ............................................................................................................... 52

5.4 Summary of assessment of transport criteria ............................................................................. 56

6 Evaluation of intersection performance options ........................................................................................ 57

6.1 Approach ....................................................................................................................................... 57

6.2 Future year forecasts .................................................................................................................... 57

6.3 Existing situation .......................................................................................................................... 59

6.4 ‘Do Nothing’ Scenario .................................................................................................................. 61

6.5 ‘Do Minimum’ Scenario ................................................................................................................ 62

6.6 Optimised at-grade solution ........................................................................................................ 63

6.7 Grade-separation .......................................................................................................................... 66

6.8 Summary of intersection modelling ............................................................................................. 67

7 Discussion and recommendations for further assessment ................................................................. 69

7.1 Issues and considerations ............................................................................................................ 69

7.2 Preferred tunnel alignments ........................................................................................................ 71

7.3 Intersection appraisal ................................................................................................................... 72

7.4 Next steps ..................................................................................................................................... 74

Appendices .................................................................................................................................................................................................... 76

Appendix A Traffic volumes ....................................................................................................................... 76

Appendix B Public Transport ...................................................................................................................... 81

Appendix C Pedestrians/Cycles .................................................................................................................. 84

Appendix D Crashes .................................................................................................................................... 91

Appendix E Intersection specific assessment ........................................................................................... 99

Appendix F Tidal flow/priority lane calculations ................................................................................... 114

Appendix G Opportunities and constraints ............................................................................................ 117

Appendix H Long list options .................................................................................................................. 155

Appendix I Traffic forecast comparison ..................................................................................................... 168

Appendix J Road layout and intersection plan ........................................................................................... 169

Appendix K Preferred option layouts ........................................................................................................... 0

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May 2011

Executive summary

The Wellington Tunnels Alliance (WTA) has been commissioned by the NZ Transport Agency (NZTA) to

undertake a study and report on alignments for the duplication of Mt Victoria Tunnel as part of the wider

Roads of National Significant (RoNS) projects covering the Wellington Northern Corridor. The outcomes are

deemed to be consistent with the recommendations of the Ngauranga to the Airport Strategic (N2A) Study

in which this project was identified. A map of the study area is included at the back of this report in

Appendix J.

As part of the initial scoping report stage, a long list of route alignment options was developed and

investigated. Each alignment option was evaluated against a predetermined multiple criteria framework

which reflected the objectives of the higher level RoNS Northern Corridor and project specific objectives.

The RoNS objectives for the Mt Victoria to Cobham Drive corridor include improving access to and from

the Wellington CBD, to the airport, the eastern suburbs and the regional hospital, in addition to providing

for better route security. The proposed highway enhancements will offer improved reliability of travel and

faster journey times on the section of SH1 from Mt Victoria Tunnel to Wellington Airport. Route security

will be enhanced by providing a second tunnel bore which will increase the ability to maintain traffic flow

during major incidents and therefore add to overall network resilience.

The key objectives of this Transport Technical Report include:

� Describing present operating conditions and an assessment of the ability to meet 2026 projected

demands

� Providing forecast traffic volumes to determine the appropriate number of lanes through the Mount

Victoria hillside

� Determining the necessary improvements to intersections between the eastern portal of Mt Victoria

Tunnel and Evans Bay Parade/Cobham Drive and proposing both an at-grade and grade-separated

arrangement to improve the level of service (LOS), achieving urban fit and a value for money solution

� Evaluating the various tunnel alignments and intersection improvements against the transport

objectives developed as part of the overall option evaluation framework

� Providing a fully integrated transport solution which supports public transport initiatives and

dedicated infrastructure for pedestrians and cyclists

� Supporting the objectives of the wider Ngauranga to Airport Strategic Study and the Government

Policy Statement (GPS).

This report sets out the background information for the study area relating to traffic volumes and

characteristics, and safety information - including detailed crash statistics, walking and cycling patterns

and public transport services.

Descriptions are given of the assessment criteria with direct relevance to transport issues and the scoring

of each option against the various criteria has been discussed in detail, to provide transparency into the

rigorous process behind the assessment.

Page iv


May 2011

Tunnel alignment recommendations

Based upon the option evaluation conducted on duplicate tunnel alignments – including their ability to

minimise impacts on affected communities and land take, and to facilitate upgrading intersections to

accommodate projected future demands - Options 3A, 3B, 5A and 5B appear to be the most favourable

schemes to be taken through to the next stage of assessment.

Intersection appraisal

At 2026, two lanes in each direction with traffic signal-controlled intersections fail to provide the desired

level of service. The provision of three lanes overcomes this deficiency but creates a large footprint around

each intersection once additional turning lanes are provided.

Grade separation, as expected, provides an acceptable level of service along the route length, but requires

provision of ramps to accommodate key turning movements. Grade separation of the state highway means

the highway has a significant footprint on surrounding land and involves a substaintial increase in price

over at grade solutions. Grade separation has not been identified as providing value for money.

Our approach has been to provide for at-grade intersections wherever possible, to minimise land take but

ensure that all intersections are future proofed to allow for future upgrade.

Some examples of arrangements to suit Options 3A, and for both at grade and grade separated

intersection treatments, are provided in Appendix K (Figure 0-2 to Figure 0-4). An arrangement for the

one-way, single bore, diagonal tunnel is shown in Appendix K (Figure 0-6). It becomes evident that the

additional length and associated cost of Option 5A and 5B need to be compared to the intersection

upgrades required on Ruahine Street and the associated additional land take.

Factors influencing choice of option

Certain factors need to be considered in any decision-making process. These include:

� The at-grade or grade separation intersection improvements should facilitate access between the

state highway and local communities.

� The intersections should support the movements between adjacent local communities. Any upgrade

of the state highway network should reinforce its intended functionality.

The options need to take a sympathetic view of land take and look for minimal land take opportunities.

Other issues include:

� Cost sensitivity

� Compromise between 70km/h and 50km/h speed limit; and

� The ability to stage the physical improvements and ensure that they are future-proofed to

accommodate any subsequent upgrades.

Page v


May 2011

Recommendations

The WTA team intend to provide an in-depth Scoping Report for the short-listed options which will

resemble that developed by Opus for the Basin Reserve Upgrade. The key changes, in terms of the

transport appraisal to be reflected in the final Scoping Report, include:

� A 2009 validated SATURN model which has been subject to external peer review which will be used to

understand the effects of future year demands on various network arrangements.

� The demand matrices fed into SATURN will need to reflect an agreed land use. At present, the WTSM

2026 land use has been adopted for preliminary assessments.

� Additional analysis of origin/destination movements covering local adjacent communities and

refinement of ramp connections to ensure that key demands are met and lengthy detours are

avoided.

The effect of ramp connections on the local road network and the design of affected portions to ensure

that planned public transport, walking and cycling improvements can be progressed without any

detrimental effects arising from increased local traffic movements.


May 2011

1 Introduction

The Wellington Tunnels Alliance (WTA) has been commissioned by the NZ Transport Agency (NZTA) to

refurbish the Mt Victoria and Terrace Tunnels to improve public safety and the operational life of the

tunnels’ infrastructure.

As part of the investigations of options for the refurbishment of the Mt Victoria Tunnel, it was identified

that increased safety might be achieved (in part) by providing egress cross passages from the road tunnel

to a new parallel tunnel, in the event of a major incident (such as a fire) in the tunnel. A secondary

advantage of a new parallel tunnel is that the user experience for pedestrians and cyclists could be

improved by a new, wider passageway, not subject to the fumes and noise from vehicles as within the

current tunnel.

In May 2010 the NZTA Value Assurance Committee (VAC) asked the WTA to check that the proposed

location for a future pedestrian/cyclist tunnel did not prejudice the optimum location of a future tunnel

from Mt Victoria to Hataitai, understood to be a “10-year horizon” project under the Roads of National

Significance (RoNS)). Subsequent to this request, in June 2010 WTA was asked to undertake a study and

report on alignments for the Mt Victoria to Cobham Drive corridor, such that statutory approvals under an

EPA process could be obtained in the future as part of a wider designation of an upgraded road corridor

from the Terrace Tunnel to the Airport.

The Mt Victoria to Cobham Drive Study is to be undertaken in accordance with the NZTA’s standard

Investigation & Reporting (I&R) procedures, with a number of initial alignments being identified and

assessed through a Scoping Report which will recommend several alignments for further investigation.

Once the NZTA has accepted the recommendation of the Scoping Report, more detailed investigations will

be undertaken with a preferred option recommended through a Scheme Assessment Report. The project

also requires a preliminary design of preferred alignment of additional capacity including a duplicate

tunnel in the Mt Victoria to Cobham Drive corridor, and the drafting of all statutory approvals applications

for the NZTA to lodge with the Environmental Protection Authority (EPA) in the future.

The following activities will be undertaken as part of the Mt Victoria to Cobham Drive Study (these

represent milestones in the consenting phase, pre-lodgement of statutory approval documents):

Project Inception

• Confirm Project Objectives – these are the project objectives to be included in the Notice of Requirement (NoR) for the purposes of the assessment under the RMA

• Confirm Methodology – confirmation of the process to prepare: the Scoping Report; Scheme Assessment Report; NoR and regional consents for lodgement with the EPA in the future

• Confirm study boundaries – while the study boundaries have been defined as being from the Catholic

Church near the Basin Reserve to the Evans Bay Parade/Cobham Drive intersection, for the purpose of

transport solutions, the study area is extended to the Wellington International Airport

• Confirm programme.


May 2011

Scoping Report

• Review existing information

• Develop consenting strategy

• Develop stakeholders/communications plan

• ’Blue Skies’ assessment of options

• High level technical assessments

• Multiple criteria analysis tool (MCAT) coarse screening.

Scheme Assessment Report (SAR)

• Detailed technical reports and assessments

• Road safety audit

• Detailed MCAT for short-listed options

• Peer review of final SAR

• Specimen design

• Develop detailed costs

• Economic evaluation.

Assessment of Environment Effect (AEE)/Consents

• Detailed environmental assessments

• Statutory assessment of preferred option

• Preparation of approvals documentation.

This Technical Report provides an overview of the transport issues to be addressed within the Mt Victoria

to Cobham Drive Study. It also identifies potential tunnel alignments, together with intersection

improvements to be taken through to the SAR. Information on additional analysis undertaken to date is

provided in other technical reports supporting the Scoping Report. These cover:

• Statutory approvals/statutory framework

• Environmental issues

• Engineering and construction

• Stakeholders; and

• The identification and evaluation of options.


May 2011

1.1 Background

The enhancement of the corridor between central Wellington and the Airport has been a key focus of a

number of policy documents and studies over recent years including the 2007 Regional Land Transport

Strategy (RLTS), the 2008 Greater Wellington Regional Council report titled “Ngauranga to Wellington

Airport Corridor Plan” and more recently it was recognised as one of the seven Roads of National

Significance (RoNS) in the 2009 Government Policy Statement on Land Transport Funding.

The long-term vision for this corridor described in the RLTS is:

“Along the Ngauranga to Wellington Airport Corridor, access to key destinations such as CentrePort,

Wellington City CBD, Newtown Hospital and the International Airport will be efficient, reliable, quick and

easy. Priority will be given to passenger transport through this corridor, particularly during the peak

period. Passenger transport will provide a very high quality, reliable and safe service along the Wellington

City growth spine and other key commuter routes. The road network will provide well for those trips which

cannot be made by alternative modes and will allow freight to move freely through the corridor. Traffic

congestion through the corridor will be managed at levels that balance the need for access against the

ability to fully provide for peak demands due to community impacts and cost constraints. Maximum use of

the existing network will be achieved by removal of key bottlenecks on the road and rail networks.”

The Greater Wellington Regional Council adopted the Ngauranga to Wellington Airport Corridor Plan in

October 2008. That report defined the corridor from the Ngauranga Merge and through the Wellington

City CBD to Newtown, the Eastern Suburbs and Wellington International Airport. It includes State Highway

1, major arterial routes, the railway line where the North Island Main Trunk and the Wairarapa lines merge

and through to Wellington City rail terminals, and key routes for passenger transport, walking and cycling.

Key elements of the strategy include definitions of a number of packages for improvements to the

transport network within the Ngauranga to Wellington Airport Corridor including the duplication of the

Mount Victoria Tunnel.

The seven Roads of National Significance have been given priority in the Government Policy Statement

(GPS) and include the Wellington Northern Corridor that extends from Wellington Airport to Levin, of which

a key component is the Mount Victoria Tunnel and various other projects including the Basin Reserve and

the Memorial Tunnel as shown in Figure 1-1.


May 2011

Figure 1-1: State Highway 1 improvements: Wellington Central1

1.2 Project Objectives

The NZTA has developed a hierarchy of objectives relating to the project, and depending on the outcomes

required. The hierarchy of objectives are defined as follows:

• Project Objectives developed specifically for the Mt Victoria to Cobham Drive Study which reflect

the outcomes required by NZTA as it fulfils its requirements under the Land Transport

Management Act (LTMA). The project objectives are non-statutory and are used by NZTA to

measure the effectiveness of the WTA to deliver on the outcomes requested in the project brief.

• Roads of National Significance (RoNS) Objectives have been developed by the NZTA and

approved by the NZTA Board for the entire Wellington RoNS programme. The RoNS Objectives are

non-statutory but are the outcomes sought by the Minister for those projects related to the

Wellington RoNS.

• Requiring Authority Objectives are developed for the project by NZTA as a requiring authority.

The Requiring Authority Objectives are relevant to the assessments undertaken under s.171 of the

RMA relating to the necessity of the designation.

The objectives for the Mount Victoria to Cobham Drive section include (following the above hierarchy):

Project Objectives - Mount Victoria to Cobham Drive Study

1 Source: Transportation Improvements Around the Basin Reserve War Memorial Tunnel Scoping Report Draft August

2010


May 2011

The proposed highway enhancements will improve access into and around the Wellington CBD, and

improve route security, as well as improving access to the airport, the eastern suburbs and the regional

hospital. The overriding study objectives include:

• To keep the state highway functioning effectively up to and including 2026 (based on high growth

traffic predictions); and

• To maintain or enhance the function of the surrounding area (connection with the local road

network, public transport, pedestrians, cyclists and recreation including the various activities in

the Town Belt).

RoNS Objectives - Wellington Airport to Levin

The Wellington Northern Corridor Project Summary Statement sets out the Project Objectives of the route

including:

• To enhance inter-regional and national economic growth and productivity

• To improve access to Wellington’s CBD, key industrial and employment centres, port, airport and

hospital

• To provide relief from severe congestion on the state highway and local road networks

• To improve the journey time reliability of travel on the section of SH1 between Levin and the

Wellington Airport; and

• To improve the safety of travel on state highways.

Requiring Authority Objectives - Mount Victoria to Cobham Drive Study

NZTA’s draft Requiring Authority Objectives [as at 8 April 2011] for the Basin Reserve to Cobham Drive

Project that correspond with the above RoNS objectives are:

1. To enhance inter-regional and national economic growth and improve productivity by

providing a cost and network-optimised state highway corridor between the Basin Reserve

and Wellington Airport that enables more efficient movement of freight and people from, to

and through the Wellington Region.

2. To improve access to Wellington’s CBD, key industrial and employment centres, port,

airport and hospital by:

a) improving the state highway corridor while not constraining the functionality of

the local roading network, having regard to the use of that network by cars, buses,

pedestrians and cyclists

b) within the designated area, appropriately recognising the provision of bus

transport, cycling and walking opportunities

c) beyond the designated area, not constraining the provision of bus transport,

cycling and walking opportunities; and

d) reducing the present peak period journey times to these key destinations by travel

on SH1.

3. To provide relief from severe congestion on the state highway and local road networks.

4. To improve the journey time reliability of travel on the section of SH1 between Levin and

the Wellington airport by:

i. Increasing the capacity of the state highway corridor and consequently improving

the reliability and efficiency of through traffic movement between the Basin

Reserve and Wellington Airport


May 2011

ii. Utilising traffic management systems (ITS/ATMS) within the designation to help

sustain the benefits of the Project and to provide opportunities for the better

management and enhancement of local networks.

5. To improve the safety of travel on State Highways by improving the safety for those using

the state highway corridor including enhanced provisions for pedestrians and cyclists to

cross significant traffic flows where appropriate.

NZTA is currently reviewing these draft Requiring Authority Objectives. NZTA’s overall objective for the

Basin Reserve to Cobham Drive Project is to secure all the statutory approvals required to construct,

operate and maintain the project and with conditions that are acceptable.

1.3 Report purpose and structure

The Traffic and Transport Technical Report sets out to:

� Describe present operating conditions and an assessment of the ability to meet 2026 projected

demands

� Provide supporting traffic flows to substantiate the need for a duplicate tunnel

� Determine the necessary improvements to intersections between the eastern portal of Mt Victoria

Tunnel and Evans Bay Parade/Cobham Drive and propose both an at-grade and grade-separated

arrangement to improve level of service (LOS), achieving urban fit and a value for money solution;

� Evaluate the various tunnel alignments and intersection improvements against the transport

objectives developed as part of the overall option evaluation framework

� Provide a fully integrated transport solution which supports public transport initiatives and dedicated

infrastructure for pedestrians and cyclists

� Support the objectives of the wider Ngauranga to Airport Strategic Study and the GPS.

This report sets out the background information for the study area relating to traffic volumes and

characteristics, and safety information - including detailed crash statistics, walking and cycling patterns

and public transport services.

Descriptions of the assessment criteria with direct relevance to transport issues are given and the scoring

of each option against the various criteria has been discussed in detail, to provide transparency into the

rigorous process behind the assessment. Assessment of options has been based on the long list of

options which were developed based on tunnel alignment options and broad intersection treatments

throughout the study area. This assessment is based on a high level look at each of the options and the

possible transport implications which they are likely to produce.


May 2011

2 Background information

2.1 State Highway 1- Route description

State Highway 1 (SH1) is a Road of National Significance and forms a strategic link from Wellington Airport

through to Wellington CBD and to Levin in the north and is referred to as the Wellington Northern Corridor

(Levin to Wellington Airport) – SH1. The state highway through the study area is generally two lanes wide

and extends from the Cobham Drive/Evans Bay Parade/ Wellington Road intersection in the east to the

intersection with Paterson Street/Dufferin Street at the Basin Reserve. It is approximately 2.25km in

length. The road passes through the Mount Victoria Tunnel towards the western end of the study area.

The tunnel is 625m in length and is the subject of current refurbishment works.

Although the study concentrates on the tunnel and the state highway to the east of Mt Victoria Tunnel, the

study needs to consider the impacts of the options being considered on an area that extends wider than

this to ensure that all options are consistent in terms of demands arising from other regional RoNS

projects. This includes the length of state highway ultimately between the north portal of Terrace Tunnel

to Wellington Airport. Figure 2-1 illustrates the extent of the study area.


May 2011

Figure 2-1: Study area

Figure 2-1 shows that the study area includes both the state highway and local roads, as the various

proposals could affect the management and operation of these roads and the different transport modes

which use them. It is important that these implications are sufficiently considered when evaluating the

various options. The state highway has been divided into three sections for ease of reference. A more

detailed plan can be seen in Appendix J.

Paterson Street to Taurima Street (1)

The Basin Reserve forms the western extent of the study area. It acts as a one-way gyratory system in a

clockwise direction. At the Dufferin Street/Paterson Road intersection there are two lanes on Dufferin

Street in the south-bound direction. A lane is picked up as vehicles travel in a south-west direction

towards the intersection between Rugby Street and Adelaide Road. SH1 remains three lanes as it turns to

the right onto Sussex Street. At the northern end of Sussex Street, SH1 (two lanes) tracks to the left onto

Buckle Street, while another two lanes turn right towards Cambridge Terrace.

On the eastern side of the Basin Reserve, SH1 makes a left turn from Dufferin Street onto Paterson Road.

The intersection between Dufferin Street and Paterson Road is signalised. The state highway then follows

Mt Victoria Tunnel


May 2011

Paterson Road east-bound towards the west tunnel portal. It is a four lane two-way road from the

intersection with Dufferin Street until approximately 100m prior to entering the western portal of the Mt

Victoria Tunnel where the road narrows to a single lane in each direction.

The Mt Victoria Tunnel is a two lane undivided tunnel. The traffic lanes are approximately 2.9m in width. A

walking and cycling path is provided and is situated on the northern edge of the tunnel. The shared path

is approximately 1.5m in width. The speed limit through the tunnel is 50km/h.

Taurima Street to Wellington Road (2)

To the east of the tunnel, Ruahine Street is a two lane, two-way road with a flush median. Parking is

permitted over limited lengths on its eastern side. A small number of properties access onto Ruahine

Street also on its eastern side. On the western side, access is provided into the Hataitai Park, Wellington

Rugby Union Club, the velodrome and netball courts via an access road at the Goa Street intersection. In

addition, the car park for the Badminton Club is accessed directly from Ruahine Street at its southern end.

The speed limit changes along Ruahine Street from 50 km/h at its northern end to 70 km/h for the

majority of its length. It then reverts back to 50 km/h at the southern end just prior to Wellington Road.

Pedestrians are catered for along the eastern side of Ruahine Street and along both sides of Wellington

Road. A pedestrian footbridge is located over Ruahine Street at its northern end just to the south of the

intersection with Taurima Street which links Hataitai with Hataitai Park.

Wellington Road to Evans Bay Parade (3)

At the intersection between Ruahine Street and Wellington Road, SH1 deviates eastwards following

Wellington Road down a slight gradient. Wellington Road has a single lane in each direction up to the

intersection with Hamilton Road/Kilbirnie Crescent. East of this intersection, Wellington Road becomes

four lanes. Kilbirnie Crescent provides access to Wellington Regional Aquatic Centre and forms part of the

public transport spine which extends from Kilbirnie through to Hataitai and eventually to the Wellington

CBD.

The Hamilton Road/Kilbirnie Crescent/Wellington Road and Wellington Road/Evans Bay Parade

intersections are both signalised. Both intersections operate with filtered right turn movements. Left turn

slip lanes are provided on all approaches to the Wellington Road/Evans Bay Parade intersection and on the

southern and eastern approaches to the Wellington Road/Hamilton Road intersection.

2.2 Local roads

The northern boundary of the study area extends to the north of the bus tunnel. This northern extent has

been chosen to enable a variety of alignments for a duplicate tunnel to be considered including potential

changes to the bus tunnel and local adjacent roads.

Access to the state highway is currently gained at the following intersections:

� Taurima Street Intersection (Priority controlled)


May 2011

� Goa Street (Priority controlled)

� Wellington Road (Priority controlled)

� Moxham Avenue (Priority controlled)

� Walmer Street (Priority controlled)

� Kilbirnie Crescent (Signals)

� Evans Bay Parade (Signals).

It is important, when deliberating on options, that consideration be afforded to movements between

residential areas and the state highway and between adjacent communities served by the current state

highway. Where possible, the preferred option should endeavour to maintain or enhance connectivity to

the existing local roads or provide suitable alternatives.

On the western side of the Mount Victoria Tunnel there is no connection to the local road network. To the

north and parallel to the highway, the original Paterson Street has been realigned and connects with

Brougham and Austin Streets. Only pedestrians and cyclists can get access onto the footpath on the north

of the state highway.

Immediately after the eastern portal of the Mount Victoria tunnel is the Taurima Street/Ruahine Street

intersection. This intersection provides direct connection for vehicles, pedestrians and cyclists to Hataitai

which is considered important in maintaining the character of the township.

Connection is provided at the Goa Street/Ruahine Street with a priority controlled intersection. This

intersection is particularly important during the Saturday peak period where it is the main access for the

Hataitai sports area and velodrome.

Connection is provided at Wellington Road/Ruahine Street with a priority seagull type intersection. This

intersection is particularly important as it forms the diversionary route for tunnel closures.

Connections are currently provided at the Moxham Avenue/Ruahine Street and Walmer Street/Ruahine

Street intersections. These are priority controlled. Connection to Moxham Avenue is not considered vital

as residents can access property via Hamilton Road. Access to Walmer Street is vital as it is a cul-de-sac.

Parallel to Ruahine Street is Moxham Avenue. This is classified by the Wellington City Council District Plan

as a collector road. It provides local access to Hataitai and Evans Bay and forms part of the bus route

which links to the bus tunnel. Taurima Street and Goa Street form connections between Moxham Avenue

and Ruahine Street.

2.3 General traffic characteristics

Traffic flows on the existing SH1 route have been extracted from the NZTA Traffic Monitoring System

(TMS) count database. Count locations are available for the following sites:

1. Paterson Street south of the Basin Reserve

2. Ruahine Street south of Goa Street


May 2011

3. Cobham Drive east of Evans Bay Parade

4. Calabar Road south of Caledonia Street.

The Paterson Street count site is the closest site to the Mt Victoria Tunnel. No intersections are present

between this site and the western portal of the tunnel. The flows which have been recorded at Paterson

Street represent the traffic volumes which are deemed to pass through the Mt Victoria Tunnel.

Table 2.1 summarises the annual average daily traffic (AADT) at each of the four count locations.

Table 2.2-1 Historic TMS AADT data for SH1

Equipment

type 2005 2006 2007 2008 2009 %HCV

Paterson St (South of

Basin Reserve)

Single

Loop 37702 38077 38663 38751 38960 5

Ruahine St (South of

Goa Street)

Single

Loop 32302 32807 34100 34342 34369 5

Cobham Drive (East of

Evans Bay Parade) Dual Loop 34259 34076 33970 35012 34516 5

Calabar Rd (South of

Caledonia St)

Single

Loop 22195 22090 22751 23962 22906 5

At 39,000 vehicles per day, the two-way traffic flow through the Mt Victoria Tunnel can be considered to

be at the maximum level expected for a road of this nature. This is further substantiated through the

examination of the hourly traffic flows recorded during weekdays and weekends.

Figures 2.2 and 2.3 below show a plot of the average daily traffic profiles for each of the four count sites.

Traffic volumes are highest at the Paterson Street end of the study area. Ruahine Street and Cobham Drive

share similar volumes throughout the majority of the time periods. Traffic volumes at Calabar Road drop

off to around 60-70 % of peak flows at Paterson Street.

The weekday daily profile at Paterson Street is predominantly flat with slight peaks between 7-9am and 3-

7pm. Ruahine Street and Cobham Drive follow a similar profile with slightly more pronounced peaks. Peak

flows on Cobham Drive and Paterson Street are very similar at their respected peak periods. Calabar Road

experiences a more pronounced peak during the morning and afternoon peaks.

On a typical weekend, peak traffic volumes exceed the weekday peak flows on Paterson Street, Ruahine

Street and Cobham Drive. Calabar Road experiences slightly less traffic. The traffic volumes remain high

for an extended period of the day with the peak flow occurring between 1-3pm as indicated in Figure 2.3.


May 2011

Figure 2-2 Traffic flow profile the average weekday (2009)

Figure 2.3 Daily traffic flow profile for an average weekend (2009)

2.3.1 Local road traffic

Moxham Avenue is highest at the northern end in the Hataitai Village, with an annual average daily total

(AADT) of 9600 vehicles per day, and gradually decreases in a southwards direction. The Saturday peak

period represents the worst case volumes for the northern end of Moxham Avenue, while the afternoon

peak represents the maximum case for the southern end. Taurima Street currently caters for an AADT of

6150 vehicles per day, while Goa Street carries much less (1,700 vehicles/day).

Flows on Hamilton Road vary dramatically. South of Kupe Street, Hamilton Road becomes a collector road

which has an AADT of 5,700 vehicles per day. Wellington Road, west of the state highway has an AADT of

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May 2011

9,150 vehicles per day. The Sunday peak period is the most critical time period for Wellington Road. The

AADT on Kilbirnie Crescent is 10,400 vehicles per day. A large proportion of this traffic joins the state

highway at the Kilbirnie/Hamilton/ Wellington Road intersection.

2.4 Property access

Access to properties along potentially affected routes need to be identified and considered as part of the

option development phase. Ideally, access should be maintained, although in some cases it may be

necessary to change current access patterns or provide alternative locations for access.

Only one property has access onto Paterson Street, being Wellington College. This is in the form of a

single direction exit from the internal road network. The majority of the eastern side of Ruahine Street has

restricted access conditions, although 16 properties are currently accessed from the state highway.

Restricted access controls are in place for the entire length of Wellington Road from the Ruahine Street

intersection to the Evans Bay Parade intersection. All the properties along this stretch of road currently

have access from Wellington Road and there is limited scope for access to be provided from alternative

frontages.

The Badminton Hall currently gains access from the western side of Ruahine Street. The entrance to the

34-space car park is positioned midway between the Goa Street/Ruahine Street and the Ruahine

Street/Wellington Road intersections. If widening is required, alternative access will be investigated via the

Goa Street intersection to the north.

2.5 Public transport routes

The bus routes through the study area are represented graphically in Figure 2.4. The majority of bus

services from the eastern suburbs use one of two major routes. The first involves buses travelling west

through Kilbirnie, along Constable Street to Newtown and then north along the Adelaide Road corridor.

The second involves buses heading through Kilbirnie, along Kilbirnie Crescent, through to the intersection

of Hamilton Road and then north along Moxham Avenue and through the Hataitai Bus tunnel. Once

through the tunnel, the buses travel down Pirie Street and turn right at Brougham Street. The buses then

turn left on Elizabeth Street and right onto Cambridge Terrace.

The bus tunnel currently accommodates a total of 66 buses in both directions during the morning peak

hour.


May 2011

Figure 2-3: Typical bus route through the northern study area

2.6 Walking and cycling

Walking and cycling at the western end of the study area is accommodated on the northern side of

Paterson Street. This continues through the tunnel via the shared pedestrian and cycle path. The path is

approximately 1.5m in width and accommodates pedestrian and cycle traffic in both directions.

On the eastern side of the tunnel, the footpath continues on the northern side of Taurima Street and on

the eastern side of Ruahine Street for its entire length. The majority of pedestrians and cyclists are

directed down the parallel route of Moxham Avenue which experiences significantly less traffic and offers

a more favourable walking and cycling environment.

A grade-separated pedestrian footbridge is provided from Taurima Street which offers access across the

state highway and between Hataitai Village and the netball courts, Velodrome and Hataitai Park on the

western side of Ruahine Street.

Typical bus

route


May 2011

Wellington Road has footpaths on either side of the road over its entire length. Fully signalised pedestrian

crossings are provided at both the Kilbirnie Crescent/Wellington Road and Cobham Drive/Evans Bay

Parade intersections.

Walking and cycling tracks exist over Mount Victoria, along Constable Street to the south and around the

bays to the north. These routes present substantial additional distance, travel time and in some cases

include steep grades when compared to the facility through the Mt Victoria Tunnel.

2.6.1 Origin Destination Survey

During the spring of 2009, Traffic Design Group (TDG) undertook a survey of the Mt Victoria Tunnel to

determine the number of cyclists and walkers using the tunnel and to obtain information on their route

choice and comments upon the overall quality of experience.

The daily pedestrian and cycle use for the tunnel was 638 and 385 respectively. The daily weekend flow

was lower at 334 pedestrians and 100 cyclists. The surveyed pedestrian counts through the tunnel

highlighted a tidal flow pattern, with an obvious peak in the morning peak period in the west-bound

direction. During the school and afternoon peaks, spikes in usage can be observed in the east-bound

direction. Usage of the tunnel was low at the weekend, with pedestrian and cycle usage at a consistent

level with that experienced during off-peak demands on an average weekday. Figure 2-4 indicates the daily

pedestrian and cyclist profile through the Mount Victoria tunnel. This information was surveyed in

February 2009.

Figure 2-4 Pedestrian and cyclist daily flow profile through the tunnel

Data from trips originating in the eastern suburbs was separated to establish the preferred route of travel

to the CBD, and north western areas. Table 2-2 summarises the proportion of trips which use each of the

routes.

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Total Cyclists


May 2011

Table 2-2: Proportion of trips from the eastern suburbs via various routes

Percentage of trips

Mt Victoria Tunnel 60%

Mt Alfred Saddle 10%

Oriental Parade 24%

Constable Street 6%

Table 2-2 indicates a large proportion (60%) of trips from the Eastern Suburbs currently make use of the

Mount Victoria Tunnel. Oriental Bay is the next most popular route choice, attracting 24% of users.

The surveys revealed that approximately 59% (Table 2-3) of all trips during the morning peak have a

destination in the CBD. Newtown was the second most popular destination attracting 9% of all trips. The

remainder of trip destinations were spread between various suburbs with Hataitai and Kelburn being the

most significant of these.

Table 2-3: Trip destinations from the eastern suburbs

%

CBD 58.9%

Kelburn 5.2%

Hataitai 4.4%

Newtown 9.1%

Other 22.4%

2.6.2 Suppressed demand through the tunnel

2006 census data has been analysed to establish walking trends for inner city suburbs in Wellington. The

percentage of people from a number of suburbs has been plotted against the approximate distance to

walk to the CBD. Distances have been taken from a centre point in each suburb to the Civic centre along

recommended walking routes. The analysis suggests there may be a suppressed demand in the Hataitai

suburb. A suburb around 3km from the city centre would typically expect about 20% of trips to be

walking/jogging. Walking trips make up around 9% of trips in the existing situation as can be seen in

Figure 2-5.


May 2011

Figure 2-5: Walking journey to work percentage versus distance from CBD

2.7 Safety assessment

The Crash Analysis System (CAS) database has been interrogated for a five year period covering crashes

which have occurred between 2005 and 2009. Local roads in the vicinity of the highway were included in

the assessment.

Figure 2.5 indicates the crash locations throughout the study area. Concentrations can be seen at the

majority of the large intersections namely, Evans Bay Parade/Wellington Road, Kilbirnie Crescent/Hamilton

Road/Wellington Road and Ruahine Street/Wellington Road with a slightly smaller concentration at

Ruahine Street/Goa Street and Ruahine Street/Taurima Street. The blue star icons represent crash sites,

with the larger stars representing a higher concentration or cluster of crashes.

Hataitai

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May 2011

Figure 2-6: Crash locations in study area

A number of key intersections have been assessed in more detail to establish any accident trends and

determine if a safety problem exists. Table 2.4 provides a breakdown of crashes by severity for each of

the intersections within the study area. Concentrations of injury accidents can be seen at the intersections

highlighted and are largely consistent with the crash distribution shown in Figure 2-6.

Crash Characteristics

Analysis of crash types shows that rear end crashes represent 19% of the total crashes. Rear end crashes

are typically concentrated around signalised intersections and in areas which experience congestion.

Both crossing (vehicle turning) and right turn against movements are highly represented. Typically these

crash types are common at priority controlled intersections or signalised intersections with filtering right

turn movements.

A sizeable proportion of vehicles crashed while cornering. This is significant due to a number of moderate

to severe curves found within the state highway alignment.


May 2011

Within the mid-block sections of the study area, the vast majority of crashes were related to rear-end

collisions (just under 50%). Traffic flows within the study area are at such a level that rear-end crashes

within mid-block sections could be associated with regularly reoccurring congestion.

Lane change is the next most significant movement category in the mid-block sections. Lane changing

crashes on Dufferin Street, Evans Bay Parade and Kilbirnie Crescent are the main contributors to this

figure.

Only two fatal accidents were reported over the analysis period and these occurred in 2005 and 2006.

Both fatal crashes occurred on mid-block sections of the state highway. The 2005 crash occurred south of

the Ruahine Street/Goa Street intersection and involved a pedestrian attempting to cross the road and

being hit by a vehicle. The 2006 crash occurred inside the Mt Victoria Tunnel and involved a motorcycle

rear-ending a slow moving vehicle. The motorcycle was reported to be speeding.

The vast majority of crashes involve either private cars or taxis. The previous five years of crash data

comprises of approximately 76% car/taxi crashes. Pedestrian and cycle crashes account for under 3 % of

all crashes in the study area.

Table 2.4: Crash severity at intersections within study area

Intersection Fatal

Accidents

Serious

Accidents

Minor

Accidents

Non

Injury

Accidents

Total

Moxham / Goa 6 6

Moxham / Hamilton 1 13 14

Moxham / Waitoa 1 6 7

Moxham / Wellington 1 11 12

Paterson / Dufferin 1 5 6

Ruahine / Goa 5 9 14

Ruahine / Taurima 1 5 16 22

Ruahine / Wellington 1 11 25 37

Taurima / Moxham 4 8 12

Wellington / Evans Bay 3 5 39 47

Wellington / Kilbirnie 5 33 38

Cobham / Calabar 4 5 26 35

Troy / Cobham 3 13 41 57

Cambridge / Elizabeth 2 7 9

Paterson / Dufferin 2 25 27

Brougham / Pirie 2 10 12


May 2011

Total 0 19 101 474 594


May 2011

Comparison of crashes with typical rates

Crash rates on SH1 have been compared with the rates that have been derived from prediction models

quoted in Appendix A6 of the NZTA Economic Evaluation Manual.

A summary of the results of this comparison is provided in Table 2.5 and the results are discussed below.

Table 2.5: Crash rates

Mid-

block

Ruahine St /

Wellington Rd

Intersection

Wellington

Rd /

Kilbirnie

Crescent

Intersection

Wellington

Rd / Evans

Bay Parade

Intersection

Taurima St /

Ruahine St

Intersection

Total Reported Injury

Crashes over a 5-year

period

15 12 5 8 6

Reported Injury Crash

rate

(Average Reported

Injury Crashes per

Annum)

3.0 2.4 1.0 1.6 1.2

Expected Crash Rate

(Reported Injury

Crashes per Annum)

5.8 0.44 0.81 0.78 0.85

The table shows there were 15 reported injury mid-block crashes over the past five years, equivalent to an

average yearly rate of three crashes per annum. The EEM predicts there should be 5.8 mid-block crashes

per annum suggesting the highway provides a high level of mid-block safety. It is noted that flows are

slightly outside the range for using this EEM prediction model as this model is only suitable for flows up to

24,000vpd, whereas the flows on the study area section of SH1 are generally around 35,000vpd.

At the Taurima Street/Ruahine Street intersection there has been a total of six injury crashes over the past

five years, equivalent to an average yearly rate of 1.2 injury crashes per annum. The EEM model for a

priority T intersection predicts 0.85 injury crashes per annum.

For the Wellington Road intersection there were 12 crashes over the past five years, equivalent to an

average yearly rate of 2.4 crashes per annum. This rate is very high as the EEM model for priority T

intersections predicts there should only be around 0.44 injury crashes per annum.

At the Kilbirnie Crescent Road intersection there were five crashes over the past five years, equivalent to

an average yearly rate of 1.0 crash per annum. This rate is moderate as the EEM model signalised

intersection model predicts there should be around 0.81 injury crashes per annum.

At the Evans Bay Parade intersection there were eight crashes over the past five years, equivalent to 1.6

crashes per annum. This rate is high as it is expected there would only be 0.78 crashes per annum.


May 2011

A more detailed analysis of crashes including individual intersection assessments is contained in Appendix

D.

Safety constraints and opportunities

The study should deliver an option that will provide an improved safety outcome compared to the existing

situation outlined above. It should address identified safety matters and be designed to standards that do

not result in any compromises to safety along the corridor. Specifically, it should deliver:

• Separated two-way traffic flows in the Mount Victoria Tunnel and along the SH1 corridor

• Controlled intersections at key access points along the state highway and remove any potentially

hazardous/unsafe movements in potentially hazardous locations

• Pedestrian and cyclist movements focused on controlled crossing facilities, such as traffic signals

or grade separated crossing

• A segregated pedestrian/cyclist facility of the carriageway of the state highway

• Improved efficiency of intersection operations to minimise delays and queues.

In particular, the development of options should consider and address:

• The safety and operational aspects of the right turn from Taurima Street towards the Mount

Victoria Tunnel that currently merges with west-bound through traffic on the state highway

• The capacity of the priority controlled intersections at Goa Street and Wellington Road that results

in queues and delays to side road traffic and associated safety concerns

• The safety of the continued operation of property accesses directly from the state highway

• The health and safety aspects of pedestrians and cyclists in the Mount Victoria Tunnel

• The safety of pedestrians and cyclists crossing the state highway.

• Safety improvements at the Kilbirnie Crescent/Wellington Road and Cobham Drive/Evans Bay

Parade signalised intersections.

2.8 Population growth

Opportunities for urban growth have been identified within the study area and surrounding the study area

by the Wellington City Council. Based on the 2006 Census, Wellington City’s population is around 180,000

people. Between 1996 and 2006, Wellington City’s population increased by 21,747, a 13.8% increase.

Wellington City is expected to grow at a faster rate than the Wellington region and to keep on growing

even though the rest of the region may not. By 2026, Wellington City’s population is expected to increase

by between 9,000 to 43,000 people. Over 50% of population growth within Wellington City is expected to

occur in the CBD area (in high density apartments) and 25% is expected in established suburban growth

areas at Johnsonville, Newtown and Kilbirnie. The remaining 25% is expected to occur in ‘greenfield’

northern suburbs.

The Wellington region was home to approximately 470,000 people in 2006. According to the Statistics

New Zealand medium growth scenario, the Wellington region population is set to grow by approximately


May 2011

50,000-60,000 people by the year 2026. Figure 2-7 indicates the forecast population growth for the

region based on high, medium and low growth assumptions.

Figure 2-7: Wellington Regional Population Forecast

Wellington City is expected to experience a higher growth rate than the rest of the Wellington region.

Figure 2-8 indicates the forecasted growth for Wellington City. From analysis as reported in the document

‘WTSM Input Tracking 2009’, from January 2010 Wellington City population has been tracking towards the

higher projection.

Figure 2-9 provides the change in population for each area in the Wellington region for the high growth

scenario. Data is provided in both population change and percentage change. Wellington City experiences

the highest percentage change with 1.4% per annum which corresponds to approximately 80,000

additional people living in Wellington City by 2031.


May 2011

Figure 2-8: Wellington City Population Forecast

Figure 2-9: Change in population for the Wellington region

Analysis of traffic movements has revealed that demand has already exceeded high growth forecasts

provided within the greater Wellington RLTS within the eastern suburbs. Greater Wellington and Wellington

City consequently agreed that a higher growth trip matrix within the Wellington Transport Model should

be the basis for forecasting future demand.

For the purposes of this study, NZTA and the study team agreed that the high growth projection should be

adopted to ensure the corridor will be designed to accommodate the additional traffic that would

eventuate under this scenario. If growth rates are lower, the corridor will be ‘future-proofed’ for a longer

period of time beyond 2026.


May 2011

2.9 Employment growth

Employment growth data from Statistics New Zealand has been analysed over the past four years from

2007-2010. The data indicates employment numbers have dropped for New Zealand as a whole by 1.9%.

Wellington as a region has experienced a slight decrease with a 0.6% reduction in employee numbers.

Wellington City is one of the few cities which did not follow the national and regional trend achieving a

0.6% increase in employee numbers over the four-year period. Figure 2-10 provides change to

employment numbers by region.

Figure 2-10: Change in employee numbers by region

Looking forward, several key areas of development in the vicinity of the study area are expected to

generate employment growth. The Wellington Airport is anticipated to generate a large increase in

employment (Section 2.10) in the eastern suburbs, along with subsidiary industrial development such as

the ‘Rongotai Big Box’ expected in close proximity. Growth is also expected along the Kilbirnie growth

spine with additional retail and industry creating employment opportunity.

Employment growth per region up to 2021 has been projected by the Greater Wellington Regional Council

(Figure 2-11). Wellington City is projected to experience a 10% increase in employee numbers from

133,000 (2006-2007) to approximately 146,000 by 2021.


May 2011

Figure 2-11: Projected change in employee numbers by region

2.10 Wellington Airport growth

The Wellington Airport Master Plan sets out strong expectations of growth in both passenger and freight

demands as shown in Figure 2-12 leading to a substantial growth in employment at the airport. Passenger

movements are expected to double over the next 20 years or so, from around five million trips per annum

in 2010 to more than 10 million trips per annum in 2030. Freight is expected to increase even more

rapidly from around five thousand tonnes per annum in 2008 to nearly 30 thousand tonnes per annum in

2030, almost six times the 2008 volumes.

As the majority of the travel to and from the airport is accessed along the route encompassing the Mount

Victoria Tunnel, this demonstrates a strong need to provide increased capacity on the airport routes to

provide access for these projected demands.


May 2011

Figure 2-12: Wellington Airport growth projections2

The anticipated growth to the airport is likely to have an effect on surrounding land use. Development of

industrial and retail land in the vicinity of the airport such as the Rongotai Big Box development and the

Airport Retail Park in Lyall Bay are mentioned in the plan and could add significant demands to the state

highway corridor.

2.11 Access to motor vehicles

Vehicle ownership statistics have been taken from the 2006 household census data from 2006. Wellington

City has been compared to New Zealand-wide statistics. Overall households in Wellington City have access

to fewer vehicles than the rest of New Zealand. A higher proportion of households have one motor vehicle,

with less households having access to two or three motor vehicles. Figure 2-13 shows Wellington City

vehicle access versus New Zealand wide statistics.

Figure 2-13: Access to vehicles3

2.12 Travel to work

The percentage of journey to work trips for each mode of transport for Wellington City and New Zealand

as a whole is shown in Figure 2-14. Overall Wellington City experiences a lower percentage of private

vehicle trips than the rest of the country. Approximately 40% of trips are made by private vehicle.

Wellington City experiences a much higher percentage in people making use of public transport (buses

and trains)and walking/jogging journeys with around 15% of trips. Cycling is above the country average

and accounts for 2% of journey to work trips.

2 Source: Wellington Airport Master Plan “2030 The Master Plan”, January 2010

3 Source: Statistics New Zealand, Census 2006


May 2011

Figure 2-14: Mode of travel to work4

The compact nature of Wellington City and centralised employment means the city is better suited to

public transport than most of New Zealand. The population density of the CBD (multi-storey apartment

buildings and hotels) means that walking trips are more common than national averages. Key destinations

within the study area include the CBD, the airport and associated industrial activities, Newtown to the west

and the Kilbirnie Road and Adelaide Road Growth Nodes.

Records of public transport usage over the past nine years provide an indication to the trends in

patronage. Bus transport has been experiencing a slow growth over the past decade with an average

annum growth of approximately 2.3%. Train patronage has been slightly more variable but an average

annum growth of around 1.2% can be observed. Figure 2-15 provides bus and train patronage numbers

over the past nine years.

4 Source: Statistics New Zealand, Census 2006


May 2011

Figure 2-15: Public Transport patronage5

2.13 Kilbirnie growth node

Kilbirnie Town Centre has been identified by WCC as a key growth node on the growth spine and an ‘area

of change’. Kilbirnie town centre is anticipated to experience considerable residential growth over the next

20 to 30 years. It is estimated that the Kilbirnie area will need to support an additional 1000 residents and

600 dwellings by 2031. Additionally, redevelopment and new development is proposed for key sites such

as the bus barns, the Indoor Community Sports Centre and the Airport.

The potential of the Kilbirnie town centre has been limited by congestion, and poor connection between

the key activities. The ability of this area to grow to the levels anticipated is largely dependent on the

provision of suitable access capacity.

Image source: Kilbirnie Town Centre Plan

5 Source: Greater Wellington Regional Council.


May 2011

2.14 Adelaide Road growth node

The Adelaide Road Framework outlines the vision for the

future growth and development of the Adelaide Road area. It

expects significant urban changes over the next 10-20 years

will create a prosperous and high-quality mixed-use area.

The vision provides for more residential development (to

accommodate approximately 1,550 more people by 2026),

supported by public amenities and streetscape, employment

opportunities, public transport, and a transport route that

works well for everyone.

The ability of this area to grow to the levels anticipated is

largely dependent on the provision of suitable access

capacity.


May 2011

2.15 Summary

Analysis of background information for the Mount Victoria to Cobham Drive Study area has highlighted the following issues and constraints: Local road connectivity: Moxham Avenue will remain as an important collector road. Connectivity at Goa

Street and Taurima Street are important in maintaining connectivity to Hataitai and Hataitai Park.

Connection to Wellington Road South is important as it is the current diversion route for tunnel closure. A

connection to Walmer Avenue is needed as it is a cul-de-sac.

General traffic characteristics: AADT traffic volumes are around 39000 vehicles per day in 2009 at the

western side of the study area. Daily flow profiles indicate a reasonably flat profile during weekdays with

morning peaks at around 7-9am and afternoon peaks during an extended period from 3pm-7pm.

Weekends currently experience higher peak periods than weekdays with the maximum demand around 2-

3pm.

Access: A number of properties currently have vehicle access directly onto the state highway. This creates

both side friction and a safety problem. Access from these properties should be rearranged or provided

via service lane type arrangements wherever possible.

Public Transport routes: Bus routes currently use Hamilton Road, Moxham Avenue and the Hataitai Bus

Tunnel to travel through the study area. It is important the ability for buses to travel through this corridor

is not impeded from a new road/tunnel alignment.

Walking and cycling: Surveys from the Mount Victoria Tunnel indication approximately 638 pedestrians

and 385 cyclists make use of the tunnel during the average weekday. The walking and cycling path

through the tunnel has issues with air quality, noise and inadequate width. As such, analysis has indicated

a suppressed demand because of the condition of the path.

Safety: A number of safety issues have been identified within the study area. Main problems include

intersections at the following locations: Taurima Street/Ruahine Street intersection, Goa Street/Ruahine

Street, Wellington Road/Ruahine Street, Kilbirnie Crescent/Wellington Road and Evans Bay Parade/Cobham

Drive.

Growth (population, employment, airport, growth nodes): Census data and population prediction

models indicate a high level of growth occurring in Wellington City. Wellington City is expected to grow by

about 35,000 people by 2026. Employment in the Wellington city is higher than national averages and is

growing at around 0.6%. The Airport predicts major growth in the next 20 years. Passenger numbers at

the airport are expected to double, while freight is expected to increase six-fold by 2030. Growth nodes

have been identified in Kilbirnie and along Adelaide Road. High quality transport network and connection

must be available for these areas to grow successfully.

Access to vehicles: In general Wellington City experience a lower car ownership than national averages.

There are more no car and one car households in Wellington and less multi-car households when

comparing to New Zealand wide averages.


May 2011

Travel to work: Mode of travel to work in wellington sees a significant reduction in car trips when

compared to the national averages. Trains, buses walking/jogging and cycling are all above national

averages. It is important alternative modes other than private vehicle transport are not precluded in this

study.


May 2011

3 Issues and opportunities to be addressed

When evaluating potential options covering both an alignment for the duplicate Mt Victoria Tunnel and

associated improvements to intersections between the tunnel and Cobham Drive/Evans Bay Parade

intersections, consideration had to be given to key transport issues and constraints. Opportunities

associated with the project were also identified from a multi-modal perspective for the study area. These

are discussed in detail within Appendix G.

3.1 Multi-modal use of the corridor

3.1.1 Public Transport - Buses

Under the existing situation, public transport takes the form of a bus corridor on Kilbirnie Crescent and

Moxham Avenue. The buses travel through the Hataitai township and travel northwest through the Hataitai

Bus tunnel towards the Wellington CBD. This corridor provides a good level of service for public transport

as it is predominantly separated from the significant traffic flows along the state highway. The bus tunnel

is dedicated for buses but only provides for one lane through the hillside. A signalised shuttle system

manages the tunnel to provide for both directions of travel which introduces a small amount of delay to

services.

As part of the project objectives, the corridor needs to be considered in the light of providing an

integrated and multi-modal function, which is in line with the intentions of the Ngauranga to Airport

Strategic (N2A) Study. It is to be expected that existing public transport services will be supported and

strengthened through any intersection improvements on the Kilbirnie to Hataitai public transport spine.

Similarly, WCC has developed a strategy covering the provision of both permanent and peak hour bus

lanes, some of which are planned for Moxham Avenue by 2026.

Where public transport routes cross the state highway (ie Kilbirnie Crescent/Wellington Road) measures

should be sought to offer priority to public transport.

3.1.2 Public Transport – Development

The Ngauranga to Airport Strategy study identified the need for a high quality public transport spine. The

public transport spine is intended to connect the railway station to Newtown and the Hospital. A study

investigating a range of public transport services is to be undertaken by Greater Wellington Regional

Council in early 2011. The study will inform Greater Wellington as to the preferred public transport

service and the likely form this will take. In considering alternative tunnel alignments, potential interface

designs at Basin Reserve should take into account the need to integrate with the Adelaide Road public

transport corridor which has been identified as the preferred route for a ‘Railway Station to Hospital’

service.

3.1.3 Walking and cycling

The existing walkway through the Mt Victoria Tunnel is considered substandard by the majority of users. A

patronage survey indicated users were concerned with noise, air quality and the width of the path. A


May 2011

suppressed demand has been identified as a result of the condition of the walkway. Therefore any options

need to include enhanced facilities for these users – either within a new road tunnel or a segregated

walking/cycling egress tunnel. This is discussed further in Section 3.4.

3.2 Local traffic movements and connectivity

When considering and developing options, it is important to ensure that connectivity and access between

communities and key growth areas are maintained and, wherever possible, enhanced. High-level issues

and constraints have been identified when considering access to the following areas:

• Hataitai

• Goa Street and Hataitai Park

• Kilbirnie growth area

• Local property

• Airport and associated industrial land.

3.2.1 Connection to Hataitai

The Hataitai community is likely to be affected by any duplicate tunnel option. The community will almost

certainly lose some of the connectivity with the existing state highway as a result of the duplication and

resulting widening.

In the present situation, access towards the CBD can be gained from all side roads including Taurima

Street, Goa Street, Walmer Street, Moxham Avenue or Hamilton Road. Many of the options include the

banning of one or more of these movements.

The removal of certain movements will place additional pressure on the remaining permitted movements.

This may result in additional vehicles making use of the internal links such as Moxham Avenue and Goa

Street. The likely routes which Hataitai residents will need to travel in order to gain access to the state

highway and the effects this traffic has on public transport routes, pedestrian and cycle amenity, will need

to be considered.

Connectivity to Hataitai must be provided to a reasonable level, but should be considered in the wider

corridor context. Connections from the state highway to the Hataitai community create side friction and

introduce conflict to the mainstream traffic. It is important that connections to the state highway from

Taurima Street or Goa Street for CBD-bound traffic be explored and improved and constraints should be

avoided which lead to movements from Hataitai to CBD having to exit via Hamilton Road.

3.2.2 Connection to Goa Street and Hataitai Park

Hataitai Park is a major trip contributor to the corridor. Access is currently provided at the Goa

Street/Ruahine Street priority controlled intersection. During the Saturday peak period, Hataitai Park

generates large volumes of traffic which results in delay and queuing at the Goa Street intersection. Given

that the intersection is priority controlled and the state highway flow is heavy, delays for side road users

are inevitable. During weekday peak periods the traffic associated with the park is considerably less.


May 2011

Providing acceptable access for visitors to the Park must be considered when assessing the connectivity of

options. The access arrangement needs to consider how vehicles travelling from the wider city suburbs

and neighbouring communities will access Hataitai Park from the state highway.

This is a particular concern in the grade-separated alignment options that limit access to a few specific

locations. Providing connections at Goa Street to the state highway (without a Kilbirnie connection) has the

potential to attract traffic from other areas to make use of Goa Street and Moxham Avenue to obtain

access to the state highway. The use of local roads such as Goa Street and Moxham Avenue for state

highway-bound traffic is undesirable as this will create additional conflicts, decrease the neighbourhood

amenity and will result in more vehicles using the public transport, walking and cycling corridor.

Ideally, traffic heading to and from Hataitai Park will do so from a connection at either Goa Street or at

Taurima Street. Consideration must be given to the likelihood of additional traffic using this connection as

an alternative route and in the process increasing traffic numbers on the Moxham Avenue public transport

corridor.

3.2.3 Connection to Kilbirnie

The Kilbirnie area has been identified as a growth node by the WCC. Access from the existing state

highway is currently provided from the Kilbirnie Crescent/Wellington Road and from the Evans Bay

Parade/Cobham Drive intersections.

At the Kilbirnie Crescent intersection the left turn movement from Kilbirnie Crescent and right turn from

the Wellington Road west approach are the predominant turning movements. Turning movements from

the Kilbirnie area at the Evans Bay Parade intersection are small in comparison to Kilbirnie Crescent.

Although this may well reflect the presence of the Aquatic Centre on Kilbirnie Crescent, it is considered

that Kilbirnie Crescent is the preferred connection to the neighbouring area.

Connection to the Kilbirnie growth area is vital in remaining consistent with growth aspirations in the area

and achieving the RoNS objectives. This will translate into consideration of direct accesses to and from the

state highway. The possible absence of a convenient future state highway connection at Kilbirnie Crescent

may well encourage Kilbirnie traffic to reroute through Hataitai.

3.2.4 Providing access to property

On the existing state highway corridor a large volume of property has frontage onto the state highway.

This access creates side friction and conflict between through traffic and local traffic. Designations exist

on the western side of Ruahine Street and the southern side of Wellington Road. It is likely additional

designation will be required to achieve the desired level of service and design speed. Access to property

from the state highway is undesirable and should be avoided wherever possible by the use of local service

lanes or alternative access arrangements.

Grade-separated alignments introduce additional difficulties in providing access to property. Service

lanes are required in certain circumstances but this can lead to significant increases in the width of road


May 2011

reserve increasing the impact on neighbouring property. Maintaining existing arrangements of property

gaining access from the state highway may have to be an acceptable compromise in selected cases given

the space constraints of the corridor.

3.2.5 Airport and associated industrial land

Access to the airport and associated industrial areas is provided in the most part by the state highway.

Vehicles travel east-bound through the Mount Victoria Tunnel, south on Ruahine street, East on Wellington

Road and Cobham Drive before turning right at the Calabar Road roundabout towards the Airport.

Providing high quality connection to the airport is important in maintaining/enhancing the economy of the

Wellington region.

Grade separation of the state highway reduces delay and would improve the reliability of trips to this area

but generally have a larger overall footprint. At grade solutions provide additional capacity to the corridor,

but intersections remain to constrain the network and limit capacity.

3.3 Intersection treatment

The opportunities and constraints for the design improvements of the intersections along Ruahine Street

and Wellington Road can be considered independently of the tunnel alignment options. The possible form

of each intersection can be considered as:

• At-grade (priority, signals or roundabout)

• Grade-separated with SH1 below in a trench

• Grade-separated with SH1 above on a structure.

Intersections along the route could be a combination of these, subject to physical constraints. A further

option exists to grade-separate SH1 in a tunnel (or trench) between Goa Street and the Kilbirnie/Hamilton

Road intersection. The issues, constraints and opportunities for each of these different forms of

intersection treatment are outlined below. Appendix G provides more detail considering each intersection

in turn.

3.3.1 At-grade intersections

The intersections could be priority, roundabout or traffic signal-controlled. Retaining the existing priority

control at the Goa Street and Taurima Street and Wellington Road intersections keeps their operation

simple and retains the priority for the state highway. However, access onto the state highway from side

roads becomes more difficult than at present due to higher volumes of traffic and more lanes to cross.

The existing safety issues at these intersections would remain.

Roundabouts would enhance accessibility for motorists attempting to enter the Hataitai area as turning

traffic from the state highway would have priority. However, given the predominant flows along the state

highway, there would be restricted opportunities for vehicles entering from the side roads. The

intersections are closely spaced and therefore converting all of them to roundabouts would reduce the

level of service for the state highway.


May 2011

A mixture of roundabouts and traffic signals in close proximity generally do not work well due to traffic

arriving in platoons at the roundabouts when released from the traffic signals. Equally, flows on the

various approach arms need to be balanced for a roundabout to work efficiently - which is clearly not the

case for Ruahine Street or Wellington Road. Due to the predominant flow on the state highway, pedestrian

and cycles would be disadvantaged as roundabouts do not lend themselves to controlled facilities and

convenient crossing facilities.

Traffic signals would provide priority to the state highway whilst enhancing accessibility to the local roads,

Hataitai and sports fields and largely address the safety issues at the intersections. Pedestrian and cycle

facilities can be incorporated into the phasing sequence. Introducing signals at the existing priority

controlled intersections would introduce some delay to the state highway where traffic is currently free-

flowing. It is also noted that traffic signals in close proximity to the exit of the tunnel would not be

desirable for safety reasons with possible queues back into the tunnel from the signals and making it

difficult for motorists to observe the signals through the transition when emerging from the tunnel.

3.3.2 Grade-separated in trench

Grade-separation in trench provides priority for the state highway with uninterrupted flow at the

intersections thereby enhancing the level of service at each intersection. Access to the local area would be

improved as conflicting turning flows are reduced since turning traffic is separated from the state highway

traffic. Similarly, there would be improved accessibility for pedestrians and cyclists due to the lower traffic

flows when crossing the state highway. The visual impact and noise of the state highway would be

reduced as the road at the intersections would be located within a trench. The intersections would be

larger in scale due to the provision of ramps, retaining walls etc. There are practical constraints due to

the close proximity of intersections and the topography (particularly of Wellington Road) that affect the

ability to provide full ramps at adjacent intersections which may result in limited accessibility to/from the

state highway from local roads. Structures in some locations would restrict access to private properties

that currently access directly onto the state highway unless specific service roads or provision is made.

3.3.3 Grade-separated on structure

Grade separation on elevated structures has similar opportunities and constraints to the options in a

trench. However, the key difference is the visual impact of structures and the effect of having traffic

elevated which could increase noise if sufficient noise suppression is not provided. The height of the

structures could act as both a physical and psychological barrier to moving around the area, particularly

between Hataitai and the sports grounds and town belt.

3.3.4 Tunnel between Goa Street and Hamilton Road

Given the significant amount of land take required to address the different curve at the intersection of

Wellington Road/Ruahine Street, it may be pertinent to consider locating the state highway in a tunnel

between Goa Street and Hamilton Road. This would enable the road to be aligned between Ruahine Street

and Wellington to be future-proofed to allow for a 70km/h speed limit. It is envisaged that such a

treatment may mitigate the amount of land take required under either a trench or elevated structure

arrangement.


May 2011

3.4 State Highway alignment

Many of the tunnel alignments would keep Ruahine Street and Wellington Road retained as the state

highway. Widening works would be required along these roads to accommodate future traffic flows and to

provide consistency with the tunnel cross-section and proposals west of the Mt Victoria Tunnel. Widening

could occur on either side of the roads; to the west of Ruahine Street would be in the town belt, and to the

east, land acquisition would be required. On Wellington Road, the existing designation is for widening

works on the southern side.

Currently designations exist on the western side of Ruahine Street into the Town belt land and on the

southern side of Wellington Road into the row of property between the Ruahine Street and Kilbirnie

Crescent. Whilst this designation is unlikely to be able to accommodate the proposed improvements to the

state highway for most options, the widening has been assumed to take place on the side of the road

which the designation is placed (i.e. west of Ruahine Street and south of Wellington Road). This

assumption will be challenged and evaluated, should widening be required over this section, using the

MCA tool once the preferred tunnel alignment is established.

A potential tunnel alignment, Option 7, could utilise Moxham Avenue and Hamilton Road for the east-

bound state highway traffic. This would remove the requirement for widening of Ruahine Street as

Ruahine Street would be used for west-bound traffic towards the existing Mt Victoria Tunnel and Moxham

Avenue for east-bound traffic. These roads would therefore form a one-way pair. By utilising Moxham

Avenue for state highway traffic there would be increased traffic volumes through Hataitai. There are

numerous private accesses and local streets that emerge onto Moxham Avenue and Hamilton Road, and

Kilbirnie School also fronts onto Moxham Avenue. This could affect the level of service along this route

for the state highway. Bus services would be affected with west-bound buses diverted onto Ruahine Street

which is distant from the centres of demand. The priority they currently receive would therefore be

reduced. Increased traffic along Moxham Avenue affects the existing preferred pedestrian/cycle route

which is located away from the higher traffic volumes. Most importantly, properties between Ruahine

Street and Moxham Avenue would effectively become land-locked with heavy traffic passing down both

sides. Having parallel adjacent one-way pairs is not the most desirable form of transport solution.

3.5 Pedestrian and cyclist options

Currently the Mt Victoria tunnel contains two 2.9m wide traffic lanes, with a 1.5m wide footpath. If the

footpath was removed and the associated width used to widen the traffic lanes, this would result in two

3.5m lanes and two 150mm shoulders. Given that the existing combined pedestrian/cycling footpath

within the Mt Victoria Tunnel is to be removed, consideration needs to be given to how pedestrians and

cycling facilities could be provided between Hataitai and Basin Reserve. These include: the use of existing

tunnel infrastructure, inclusion within any new duplicate tunnel and alternatives over Mt Victoria. These

are discussed below.


May 2011

3.5.1 Pedestrian/Cycle Use of Existing Bus Tunnel

Using the bus tunnel provides a dedicated facility utilising existing infrastructure and segregates them

from general traffic. This option assumes buses will be removed from using the bus tunnel and will be

provided for in the duplicate tunnel. The tunnel would require upgrading for sufficient lighting, surfacing

etc to be suitable for use by pedestrians and cyclists. The tunnel requires negotiation of steeper gradients

and does not appear to be as conveniently located on the desire lines of those users of the existing Mt

Victoria Tunnel.

3.5.2 Pedestrian egress tunnel between existing tunnel and new parallel tunnel

A purpose-built tunnel must be of sufficient width to cater for both pedestrians and cyclists. Current

pedestrian and cyclist demand guidelines, such as Austroads, indicate a path width of 4.0m is needed.

The tunnel would ideally be on the preferred desire line of existing tunnel users and would provide

enhanced amenity and environment away from traffic. Such a tunnel would be dual purpose being a

dedicated tunnel for these users plus being available for emergency egress of the adjacent vehicle

tunnel(s). If the tunnel is sandwiched between two road tunnels, careful design would be required at each

end to ensure that it ties into pedestrian and cycle routes safely. There is also a need to have tunnels in a

similar vertical plane to facilitate access between the two adjacent road tunnels.

3.5.3 Pedestrian/cycle facilities over Mt Victoria

A route over the top of Mt Victoria would enhance links between Hataitai and the CBD, particularly for

leisure use and those people who do not want to use the tunnel. Through adequate surfacing and

lighting, a route over the top provides an alternative facility. However, the route is steep, exposes users

to the weather and would not necessarily be suitable or desirable for all users.

3.5.4 Link between Mein Street (Newtown) and Alexandra Road/Wellington Road

A link would enhance accessibility for pedestrians between Hataitai, Newtown and the Hospital. It is

located within the town belt and therefore would need to be constructed sympathetically.

3.5.5 Gondola over Mt Victoria

A gondola would provide an alternative to walking through a tunnel. It would be accessible to people of a

variety of fitness levels. It would be a secure facility that would be monitored and enhance the experience

of travelling between Hataitai and the CBD. There is the opportunity that it could be used primarily as a

tourist attraction. However, during bad weather such as strong winds, the gondola would not be able to

operate. It would be located within the town belt and therefore would have impact on this land and the

look of the town belt from the city. The gondola may not be able to carry cyclists due to having to

transport their bicycles.


May 2011

3.6 Public transport use of tunnels

Consideration needs to be given to how public transport operations could be affected by the provision of a

duplicate tunnel under Mt Victoria. Currently, public transport is afforded priority through a dedicated bus

tunnel which links to a strong public transport spine between Hataitai and Kilbirnie. Possible

opportunities for public transport vehicles within future tunnel arrangements are discussed below.

3.6.1 Retain buses in existing bus tunnel

Existing priority for buses through Mount Victoria would be protected as buses would use the existing

corridor which only caters for local traffic. Infrastructure is already in place and only regular maintenance

works would be required for the tunnel. Increased numbers of buses using the tunnel may increase delays

due to ‘shuttle working'.

3.6.2 Buses in existing Mount Victoria tunnel/duplicate tunnel

Buses using the traffic tunnel would benefit from not having shuttle working in the bus tunnel. Buses

would only be advantaged if they have their own dedicated lanes and appropriate links to the local road

network are provided at each end of the tunnel. New infrastructure would be required through the tunnel

for overhead wires for the trolley buses; this could be installed as part of the refurbishment works.

3.6.3 Express bus services

There is the inherent assumption made that express bus services could make use of a duplicate tunnel.

There may be travel time benefits arising from use of the tunnels assuming the support infrastructure can

be provided and installed.

3.7 Travel demand management

Opportunities have been sought to identify travel demand management measures which may lead to

operational improvements of the corridor. Maximising the use of an asset supports key fundamental

principles of the LTMA and GPS.

The following measures have required early consideration within the study and, in some cases, have

dictated the provision of lanes within any future tunnel. More details and calculations can be found in

Appendix F.

3.7.1 Tidal flow

Initial evaluations of future demand were undertaken to determine the provision of traffic lanes. An

opportunity was taken to investigate the possibility of introducing tidal flow around a probable ‘2 plus 1’

arrangement.

A tidal flow system would provide additional lanes in the predominant peak traffic flow direction by

utilising one or more lanes in the non-peak direction. The available capacity of the lanes in the peak and


May 2011

non-peak directions therefore need to be sufficient for such a system to operate satisfactorily. Through

examination of forecast traffic flows, it became evident that the volume of traffic in the non-peak traffic

direction (approx. 2250 veh/h) exceeded the capacity of a single lane and produced LOS(F). This results in

two lanes being required in the non-peak direction. From this it can be concluded that the balance of

traffic volumes is not suitable for a three lane tidal flow system and that a minimum of four lanes are

required (two in each direction).

3.7.2 Priority vehicles lane

Duplication of the existing Mt Victoria Tunnel provides potential opportunities for using one or more of

the lanes as a priority vehicle lane. Such a lane may include bus lanes or high occupancy vehicles. As

outlined above, at least two lanes are required in each direction through Mount Victoria Tunnel. Use of

one of these lanes as a bus lane would result in the remaining traffic lane significantly exceeding its

capacity and therefore a bus lane would not be appropriate.

Through initial analysis, the forecast traffic volumes indicate the existing and duplicate tunnel operating

at capacity (approx. 1600veh/h/lane) with two lanes in each direction. Existing surveys indicate vehicle

occupancy of 1.3 in Wellington city. This means up to about 1540 vehicles could currently be occupied by

more than one person making them eligible for a two person plus (2+) HOV lane.

For a high occupancy vehicle lane to work it would need to be restricted to 3+ people per vehicle. For

operation of the general traffic lane to remain acceptable, approximately 1000 vehicles would be needed

to make use of the 3+ HOV lane. This is not considered realistic, especially given the limited benefits an

HOV lane will provide over the short distance. Problems associated with weaving are likely to reduce the

benefits further for users.

3.7.3 Bus priority at traffic signals

Priority for buses at traffic signals would speed up the passage of buses through key intersections. This is

simple to implement and requires little additional infrastructure. The main bus corridor is along Kilbirnie

Crescent, Hamilton Road and Moxham Avenue. Therefore, the buses would only benefit at the

SH1/Hamilton Road intersection and thus limited time savings are likely to be achieved. The long-term

provision of bus lanes in Moxham Avenue is included within the Wellington City Council list of bus

improvements.


May 2011

4 Options identified

Project team analysis and workshops attended by technical experts and stakeholders were used to identify

and develop a number of options for the corridor. A large number of options were identified, along with

complimentary transport measures across the study areas that are categorised according to the following

fields:

• Alignments (tunnels & roading)

• Walking & cycling

• Public transport

• Environment

• Land use.

Following the workshop, an extensive list of transport measures and route options were refined in

response to the project design directions and the influence of social, environmental and physical

opportunities and constraints. The list was developed using the eastern side of the Basin Reserve as a

starting point. The eastern boundary of the project was taken to be at the Cobham Drive and Evans Bay

Parade intersection.

A geometry assessment using MX road design software was used to develop 3D models of the various

alignment and intersection options and to refine the options ensuring that proposals were practicable.

This was undertaken in parallel to the qualitative assessment of options.

The options for alignment of a duplicate tunnel are shown in Figure 4.1 and are described in more detail

on the following pages. For each tunnel alignment option, at-grade and grade-separated arrangements

along Ruahine Street and Wellington Road were considered.

At this initial stage, tunnel alignment options which require widening on Ruahine Street and Wellington

Road have been assumed to take place on the western side of Ruahine Street and the southern side of

Wellington Road, so to follow the intention of the existing designation. This assumption will be revisited

once tunnel alignment options have been narrowed down.


May 2011

Figure 4.1 Duplicate tunnels options

‘Do Minimum’ option

The ‘Do Minimum’ scenario assumes no improvements to capacity through the tunnel would be offered.

This would result in the tunnel remaining as the key constraint through this section of the corridor. The

walking and cycling facilities within the existing tunnel would remain. Four lanes (two in each direction)

would be provided between Taurima Street and the Wellington Road/Kilbirnie Crescent intersection.

Traffic signals would be introduced at the following intersections:

• Taurima Street/Moxham Avenue intersection. Right turning lane added to the north Moxham

Avenue approach.

• Goa Street/Ruahine Street. Localised widening at the intersection to include right turning lanes on

the Ruahine Street approaches. Two approach lanes on Goa Street.

• Wellington Road/Ruahine Street: Dual right turn lanes on Wellington Road west. Right turn lane on

Ruahine Street and left turn slip on Wellington Road south.

• Walmer Street/Wellington Road: Single lane approach on Walmer Street.

The majority of movements at the Taurima Street intersection are banned leaving a left in turn into

Taurima Street. The intersection between Wellington Road and Moxham Avenue is closed completely.

The ‘Do Minimum’ option is largely similar to the Project Feasibility Report done by Opus in June 2010,

but contains a number of changes. All widening has been designed to be completed within the current

designation.

Option 1 – Widen existing Mt Victoria Tunnel

An enlarged tunnel would provide four lanes (two lanes in each direction). The additional width could

include bus/priority lanes. Pedestrians/cycle facilities could be included within a dedicated passageway in

the enlarged tunnel or as a separate egress tunnel parallel to the existing tunnel. Construction of the

widened tunnel requires closing of the tunnel for a considerable period during construction.


May 2011

Option 2: Pirie Tunnel

A duplicate tunnel would be constructed from the north of Pirie Street to Taurima Street. The new tunnel

would accommodate east-bound traffic, while west-bound traffic would continue to use the existing Mt

Victoria Tunnel. This implies Vivian Street would remain as the strategic route for east-bound state

highway traffic. East-bound vehicles on the Inner City Bypass (ICB) would proceed straight up Pirie Street

rather than making a right turn towards the Basin Reserve.

A suitable emergency egress would need to be provided for the tunnel. If this were to be used as a new

pedestrian/cycle route it would result in longer travel distances and times and be less convenient for these

users. In addition, there would be a more significant grade along the tunnel for pedestrians and cyclists

compared to the existing walkway.

This option involves the use of Pirie Street by state highway traffic travelling towards the tunnel as well as

buses using the bus tunnel. Pirie Street is a residential street with significant bus traffic (up to 60 buses

per hour at peak).

Option 3A – New tunnel parallel and north of the existing tunnel

Option 3A creates a duplicate tunnel adjacent to the existing Mount Victoria Tunnel to the north. This will

create a one-way two-lane pair. This would involve the conversion of the existing tunnel from a two-way

operation to a one-way operation west-bound. The duplicate tunnel would require a minor realignment in

the Basin Reserve (easing the east-bound left-hand turn lane from the Basin Reserve to Paterson Street,

using land already owned by the NZTA).

The duplicate tunnel could include a pedestrian/cycle passageway that could be used as an emergency

egress from the existing tunnel if a separate pedestrian/cycle tunnel is not constructed adjacent to the

existing tunnel. Providing that an adequate level of service is reached in the tunnel, express bus services

could use the traffic tunnels rather than the bus tunnel.

Option 3B – New tunnel parallel and south of the existing tunnel

Option 3B creates a duplicate tunnel adjacent to the existing Mount Victoria Tunnel to the south. This will

create a one-way two-lane pair. The southern tunnel would require construction of a western portal

beneath the Wellington East Girls College (WEGC) site.

This option has similar characteristics as Option 3A, although if pedestrian/cycle facilities are provided in

a southern tunnel, these are in a less favourable position for linking to the local road network, particularly

into Hataitai. If a pedestrian/cycle tunnel is constructed to the north of the existing tunnel, an emergency

egress tunnel for the new southern tunnel may not be required if cross passages are provided between the

new and existing tunnel. A key challenge with a southern tunnel is connectivity at the eastern end where

the radius joining the tunnel to Ruahine Street is prohibitively sharp.

Options 4A, 4B and 4C: Two bore tunnel from Paterson Street/Basin reserve to Wellington

Road

Option 4A involves a new four lane tunnel running from its western portal beneath the Wellington East

Girls College (WEGC) site on Paterson Street to the corner of Wellington Road and Ruahine Street. The

eastern portal will include changes to the Ruahine Street/Wellington Road intersection with land required

on both sides of the existing roadway.


May 2011

Option 4B continues onwards below ground from Ruahine Street to emerge just west of the Wellington

Road and Kilbirnie Crescent intersection. It should be noted that westward of this intersection if the

roadway is to be two lanes in both directions, diversions around a portal may involve some widening in

the design. The continuation of the tunnel in comparison to Option 4A includes passing beneath a

significant number of residential properties fronting the northern side of Wellington Road.

Option 4C involves a further continuation of the tunnel to emerge to the west of the Wellington

Road/Evans Bay Parade intersection. This will involve less widening but will still be located in an already

busy area. Additionally more properties will be located above the additional tunnel in the residential areas

of Hataitai.

These alignments would remove the majority of traffic from Ruahine Street allowing this road to be access

or local traffic only, significantly improving links between Hataitai and the Park/sports grounds and town

belt and also the amenity of the whole area. The existing Mount Victoria Tunnel could be used by buses

enabling them to link into Brougham Street and back onto their existing route through Mount Victoria

residential area. This would avoid delays associated with the shuttle working at the existing bus tunnel

although overhead cables would need to be provided in the tunnel for the trolley buses. If buses are

relocated into the existing traffic tunnel, the bus tunnel could be converted for use by pedestrians and

cyclists. However, this route results in steeper gradients and is not as convenient for those travelling to

the schools or university. These options result in minimal change to Ruahine Street and adjoining land

use.

Both portals in all three options require new construction and the tunnel itself will be a new bore. An

important consideration for this option is the prediction of queues travelling east-bound under an at-grade

option (for Ruahine Street/Wellington Road) which may well extend back inside the tunnel.

Options 5A, 5B and 5C: Single bore tunnel from Paterson Street/Basin reserve to

Wellington Road

This option involves a diagonal tunnel from Paterson Street to the Ruahine/Wellington Road intersection,

as in Option 4. The difference is that the tunnel itself will be two west-bound lanes only. West-bound

traffic would be removed from Ruahine Street and transferred into the new tunnel. This would remove the

requirement for four lanes on Ruahine Street with resulting improved access between Hataitai and the

sports area and town belt. Intersections would be simplified along Ruahine Street as this would become

one-way southbound. Access to the tunnel from Newtown via Wellington Road may possibly be restricted

but could be provided via another intersection.

Option 5B and 5C involve the extension of the new tunnel to the west of the Kilbirnie/Hamilton Road

intersection (Option 5B) or to the west of the Cobham/Evans Bay Parade intersection (Option 5C). The

alignments have similar opportunities and constraints as Option 5A but access to and from the local road

network would be restricted to the new tunnel due to physical constraints in providing safe and efficient

intersections and connections to the new tunnel. Access via Ruahine Street would disappear and would be

focused on Kilbirnie/Hamilton and Evans Bay/Cobham Drive.

A key challenge for the longer tunnels is providing access for Hataitai and Kilbirnie residents to the west-

bound tunnel.

Option 6: Single bore Paterson Street to Ruahine Street (adjacent to Goa Street) with

existing tunnel remaining


May 2011

This option has a similar western portal to Options 3B, 4 and 5 above. However the new tunnel emerges

at an eastern portal located on Ruahine Street in the region of the existing Goa Street intersection. The

location of the eastern portal is close to the existing Badminton Hall buildings and access to the Hataitai

Park sports facilities and will have a significant effect on the town belt land.

Reduced traffic on Ruahine Street north of Goa Street removes requirement for four lanes between Goa

Street and the existing tunnel. Accessibility between Hataitai and the sports grounds would be improved

on the northern section of Ruahine Street due to reduced traffic. Although pedestrian/cycle facilities

could be provided through the new tunnel this would not be on the main desire line.

Option 7: Widening of the existing bus tunnel

Option 7 involves widening the existing Bus Tunnel to allow two east-bound lanes. The existing Mt

Victoria Tunnel will remain as the west-bound link. Ruahine Street will become the west-bound route while

east-bound traffic will be diverted down Moxham Avenue forming a one-way pair. A new pedestrian and

egress tunnel will be constructed parallel to the vehicle tunnel.

Construction will include closure of the bus tunnel but with the existing Mt Victoria Tunnel as an

alternative. As with Option 2, improvement and widening of Pirie Street will be required. Bus services will

suffer significantly as they will be forced to join general traffic. Connectivity and severance of the Hataitai

community is likely to become a key issue with significant additional traffic on Moxham Avenue.

Option 8: New tunnel located beneath the existing Mt Victoria tunnel

This option involves construction of an additional tunnel beneath the existing Mt Victoria Tunnel as two

east-bound lanes. The existing Mt Victoria Tunnel will remain as the west-bound lanes. The footprint of

the tunnel itself will remain essentially unchanged. However both portals will require modification and

widening. A new pedestrian egress will be constructed.

Key considerations will be careful design to allow satisfactory vertical separation between the two

directions and to avoid steep grades to achieve the desired alignment of the new tunnel. Providing an

emergency egress could be an issue due to level differences between the tunnels. The structural integrity

of the Mt Victoria Tunnel is likely to be an issue and will require some sort of structural support.

Construction of the new tunnel would have a significant impact on the local road network as the existing

tunnel would need to be closed for a considerable period during construction.

Options 9: Tunnel from Ellice Street to Ruahine Street

A new east-bound tunnel alignment that uses Ellice Street provides a simplified link to the Basin Reserve.

Ellice Street will require widening and a number of residential properties will be affected. As with Options

2 and 3A the eastern portal will emerge close to the existing kindergarten. The tunnel will contain two

lanes east-bound with west-bound traffic travelling through the existing Mt Victoria Tunnel. A new

pedestrian egress tunnel will be constructed between the existing tunnel and the new.

The alignment would be less likely to have an impact on a pedestrian/cycle egress tunnel constructed

parallel to the existing tunnel due to the increase separation. However, by using residential Ellice Street,

this could sever access to the historical properties and church located on Paterson Street.

Intersection treatments considered for options

For the majority of options, four sub-options were considered related to the treatment of Ruahine Street

and Wellington Road intersection, comprising:


May 2011

� At-grade

� Grade-separated in trench

� Grade-separated on a structure; and

� Grade-separated via tunnel (from Goa Street to Kilbirnie Crescent).

A total of 50 ‘blue sky’ options were developed. These options were based on 10 main layouts (‘Do

Minimum’ and nine duplicate tunnel options) with slight variants to several of the tunnel options (as

indicated by the 3A, 3B etc) and a number of alternative intersection treatments. The complete set of long

list options is represented in Table 4-1.

Option naming convention

Options have been named according to a unique naming system. The naming system allows each option

to be expressed in terms of the alignment of the duplicate tunnel, variations in portal position of the

duplicate tunnel and treatment of intersections on the Ruahine Street and Wellington Road corridor.

The name of each option follows the following convention:

Example: 3 � − 1 ��

�� 1 − 9 � �� . � − � � − (�� 1 − 4)

Table 4-1: ‘Blue sky’ Options List summary

1. At-Grade2. Grade Separated (Trench)

3. Grade Separated (Structure)

4. Tunnel from Goa St to Kilbirnie

Cres

1 - Widen Existing Tunnel - ��

2 - Pirie Street Tunnel - ��

A - North of Existing tunnel ��

B - South of Existing tunnel ��

A - To Wellington Road Intersection ��

B - To Kilbirnie Crescent Intersection ��

C - To Evans Bay Parade intersection ��

A - To Wellington Road Intersection ��

B - To Kilbirnie Crescent Intersection ��

C - To Evans Bay Parade intersection ��

6 - Goa Street Tunnel - ��

7 - Widen the Bus Tunnel - ��

8 - New Tunnel Under Existing - ��

9 - Ellice Street Tunnel - ��

Intersection Treatment

VariationTunnel alignments

50Total options

3 - Parallel Tunnel

4 - Twin Bore Diagonal Tunnel

5 - Single Bore Diagonal Tunnel


May 2011

5 Transport evaluation framework and assessment of options

The evaluation framework provides a basis for the assessment of options and is intended to initiate

discussion over future needs and requirements. The framework provides a basis on which options can be

scored against criteria from multiple perspectives and reflects a wide range of constraints.

The evaluation criteria have been developed through a hybrid approach having regard to LTMA, RoNS

objectives, GPS and project specific opportunities and constraints which were identified in the Options

Workshop. The project team was also guided by the project objectives during the development of the

evaluation criteria. Key challenges for this type of process include choosing evaluation criteria which

differentiate between options and ensuring that issues are not reflected in more than one criteria. During

the development of the evaluation framework a number of issues and potential criteria were identified but

not incorporated in the final evaluation framework. This was for a range of reasons which included:

• The issue would not differentiate between options

• The issue was captured by other criteria already

• The issue would be affected as a matter of course (e.g. water quality inputs); and/or

• There was not enough detail at this stage in the process.

Criteria or issues identified but not incorporated into evaluation framework are noted in the discussion

criteria groups below.

In addition to considering each option against the evaluation criteria, the project team undertook parallel

analysis to consider key components that have the potential to preclude further consideration. Examples

include developing a high level cost estimate, considering geometric alignment issues for the various

intersections along the route and considering whether very low scores for one or more of the evaluation

criteria should render the option unrealistic.

5.1 Description of transport-related evaluation criteria

The evaluation criteria were split into six groups: Economic; Connectivity; Operational; Environmental;

Constructability; and Social. Full details of the evaluation criteria can be found in the “Evaluation

Framework” Technical Report. Criteria directly related to transport issues are contained within the

“Connectivity” and “Operational” groups and have been outlined below:

Connectivity

This group targets maintaining or improving access and mobility and providing connection to key land

uses whether it be by walkway or road. This group is broken down into four criteria:

� Linkages to local roads

� Access to Hataitai Park

� Integration – support of urban arterial; and

� Pedestrian/Cycle Amenity (access, experience).


May 2011

Operational

This group captures the ability of the option to move traffic and people in a safe and efficient manner.

This group is broken down into five criteria:

� Public Transport Corridor support of public transport

� Level of Service - general traffic & freight

� The ability of Hataitai residents to connect to the state highway network to/from the CBD

� Safety

� Resilience.

5.2 Assessment against transport evaluation framework

Evaluation has been carried out on each of the long list options - described in detail in Appendix H. But

essentially each of the options from 1-9 were evaluated with four sub-options:

� At-grade

� Grade-separated with main line on structure

� Grade-separated with main line in trench

� Wellington Road/Ruahine Street tunnel.

This section discusses the influence of what are deemed to be specific transport-related parameters –

namely the “Connectivity” and “Operational” groups. The rationale behind the development of an

evaluation framework and process, including the scoring and appraisal of each option against all

objectives, is described in more detail within the Evaluation Framework Technical report. The table below

outlines the scoring criteria used to assess options.

Table 5.1: Five-point scoring system

Scores Criteria Pts

++ Strong positive effects 4

+ Small/moderate positive effects 3

0 Neutral with regard to ‘Do Minimum’ 2

- Small/moderate negative effects 1

-- Strong negative effects 0

5.2.1 Connectivity

Linkages to local roads

This criterion has been developed to capture the connectivity of local roads to the state highway corridor

(see Figure 5.1 below). Each option was assessed regarding the manner in which it maintained existing


May 2011

connectivity to the local road network and addressed current conflict points. The ‘Do Minimum’ options

involved removing the right turn out of Taurima Street, but on balance scored neutral due to conflict

points. These are largely addressed by the introduction of traffic signals being negated by vehicle queuing

and additional rear-end crashes. Grade-separation of the state highway significantly reduces the conflict

points but still maintains the connection to local roads through the provision of ramp connections and

therefore scored positively. Options involving a diagonal tunnel had limited connectivity to the local road

network and generally provided connection at one or two concentrated locations, therefore scored

negatively.

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Options by code

Connectivity - Linkages to Local Roads

Figure 5.1 Local road connectivity assessment

Access to Hataitai Park

Access to Hataitai Park is obtained at the priority controlled intersection at Goa Street and Ruahine Street.

Severe congestion occurs during Saturday peak periods due to the sporting activities at the netball courts,

velodrome and rugby union club. Pedestrian access is currently obtained from the use of the pedestrian

overpass. The overpass connects the Hataitai village to Hataitai Park. No further pedestrian facilities are

provided, although informal crossing of SH1 occurs outside peak periods.

Options were assessed regarding the way they provided for vehicles, pedestrians and cyclists to gain

access to the Park – see Figure 5.2. The following issues were considered in determining a score against

this criterion for each option:

• The quality of the Goa Street intersection

• Competing vehicle movements such as through traffic

• Provision of signalised or grade-separated crossing points to assist pedestrians or cyclists

• General ease of access from the eastern suburbs as well as from the west and CBD.

All options except 6-1 (tunnel to Goa St) were considered to provide improved access to Hataitai Park. A

grade-separated state highway alignment means that through traffic no longer acts as a barrier to people

accessing the Park. Option 6-1 scored negatively due to the expected complexity of the intersection at Goa

Street.


May 2011

Figure 5.2 Hataitai park access assessment

Land use integration – support of the urban arterial

This criteria was aimed at ensuring the duplication is consistent with national and regional state highways

and reinforces the road hierarchy in the study area. Integration with existing and future land uses is also

captured (See Figure 5.3 below).

Options were scored according to their effectiveness in supporting the existing state highway network and

the manner in which they made use of appropriate corridors. Options which provided a high quality route

eliminating the existing conflict between local and strategic through traffic scored highest. Grade

separation was perceived as achieving this most favourably and so scored a double +. Options which

placed traffic on local or access orientated roads, such as Option 2 and Option 7, scored poorly.

Figure 5.3 – Land use integration assessment

Pedestrian/cycle amenity

Pedestrian and cycling amenity was scored with regard to the following factors:

• Access or ease of use, bearing in mind the desire lines of pedestrians and cyclists in the area

• Experience of users relating to air quality, lighting, odour, ventilation, etc

• Safety of users

• Infrastructure provision including width of path, on road or off road and intersection treatments.

The majority of alignment options represented an improvement over the ‘Do Minimum’ scenario, as they

had an alternative space for pedestrians and cyclists in a duplicate or egress tunnel. The existing tunnel is

considered to be below an acceptable standard with regards to safety, width, air quality and lighting.

The treatments of the alignment options fall into one of three categories:

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Connectivity - Access to Hataitai Park

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Options by code

Connectivity - Land Use Integration


May 2011

• New egress tunnel adjacent to existing tunnel

• Provision for pedestrian and cyclists within a duplicate tunnel

• Use of the Hataitai Bus tunnel.

Although each of these three treatments are likely to present similar levels of service and amenity

through the tunnel, treatment at either end, network connections and traffic conditions vary between

options – see Figure 5.4. Options which make use of the Moxham Avenue corridor as a pedestrian/cycle

route and remove through traffic scored highly. Options which required pedestrians and cyclist to share

road space with the state highway traffic scored negatively (Option 7). An egress tunnel which was placed

in between the existing tunnel and a duplicate tunnel (as in Option 3A) was assumed to have a decreased

delay associated with the treatment at either end of the tunnel, as the walkway would need to pass over or

under state highway traffic.

Figure 5.4 – Pedestrian and cycling amenity assessment

5.3 Operational assessment

Public Transport Under the existing situation, public transport takes the form of a bus corridor on Kilbirnie Crescent and

Moxham Avenue. The buses travel through the Hataitai township and travel northwest through the Hataitai

Bus tunnel towards the Wellington CBD. The ‘Do Minimum’ scenario assumes bus priority measures to be

implemented along Moxham Avenue and at the Kilbirnie Crescent/Wellington Road intersection. This

represents an improvement over the existing situation.

The majority of options retain the existing bus corridor along Kilbirnie Crescent and Moxham Avenue with

planned priority improvements (baring Option 2 and 7), providing an improvement to the public transport

corridor. A point of difference between options occurred at the Kilbirnie Crescent intersection. A grade-

separated state highway provides a higher level of service to buses travelling through the Kilbirnie

Crescent/Hamilton Road intersection towards Moxham Avenue as reduced flows on Wellington Road will

offer more green light time to Kilbirnie Crescent traffic.

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Connectivity - Pedestrian and cycling amenity


May 2011

Figure 5.5 – Public transport operations assessment

Level of Service

Level of service (LOS) has been measured at each of the intersections – see Figure 5.6. Traditionally the

LOS through an urban corridor characterised by stop and starts at intersections is measured by assessing

the average speed of a vehicle moving through the corridor. As an initial assessment of the network

options, LOS from each of the intersections has been assessed using the SIDRA intersection modelling tool

– see Section 6. The level of service of options which do not contain at-grade intersections have been

estimated based on anticipated maximum service flow rates associated with a pre-selected design speed.

At this level of assessment, the traffic demands between options do not change significantly. The options

which have been developed all provide a similar level of traffic lanes in each direction. Therefore the LOS,

as estimated at the midblock sections, does not differentiate very much between options.

The LOS of the at-grade intersections along the corridor has been assessed using SIDRA for the 2026

morning and afternoon peak periods. The SIDRA assessment has highlighted that the LOS of the

intersections is highly sensitive to the frequency of pedestrian movements. Section 6.5 provides a

summary of ‘Do Minimum’ LOS at each intersection. The ‘Do Minimum’ represents upgrades which can be

implemented without significant land take or realignment. The at-grade option for each tunnel alignment

assumes that the ‘Do Minimum’ intersection upgrades are implemented.

A number of intersections under the ‘Do Minimum’ scenario operate at LOS (F) while selected intersections

operate with a LOS (E). LOS criteria is based on the corridor as a whole but, on balance, the corridor is

considered likely to achieve a LOS (E/F) with at-grade intersections. At-grade intersections associated with

Options 4B and C will operate at LOS (E/F) but, on balance, due to the limited number of signalised

intersections the corridor is considered to operate at LOS (D/E). At-grade intersections for Option 5

operate at a LOS (D-F). On balance, the corridor will operate at a LOS (E).

Grade separation allows free-flow traffic and would be expected to achieve a LOS (C/D). This has been

assessed using the Austroads Guide on Capacity (freeways) for a design speed of 80km/h. A score of 2

represents a LOS of D, a score of 1 represents a LOS of D/E and a score of 0 corresponds to LOS E/F.

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Operational - Public Transport Corridor


May 2011

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Level of service - Highway operating conditions

Figure 5.6 – Level of service (LOS) assessment

Hataitai Connection

Under the existing situation, Hataitai residents enjoy a good level of connectivity to the state highway,

Hataitai Park and Kilbirnie. The duplication project could possibly decrease the connectivity of the Hataitai

community.

Property access along the existing state highway is undesirable and creates side friction which decreases

capacity and creates safety concerns. The duplication of the Mt Victoria Tunnel will attract additional

traffic to the state highway corridor and provide a barrier for the access of Hataitai residents to key

destinations.

Options were scored against their ability to provide connectivity to Hataitai and their effect on travel times

for residents. The ‘Do Minimum’ option is perceived to result in longer travel times for Hataitai residents

due to the congested nature of the network. Options 4C and 5C are not considered to provide adequate

connection to Hataitai since the tunnel portal is positioned west of Kilbirnie intersection and therefore

these options scored negatively. Grade separation of state highway traffic allows improved access at

certain locations and removes connections at others. On balance, grade-separated options were scored

neutrally.

Figure 5.7 – Hataitai connection assessment

Safety

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Options by code

Operational - Hataitai Connection


May 2011

Within the existing study area, crashes are clustered around several intersections. The stop and start

nature of the signalised intersections results in a large proportion of rear-end type crashes. High crash

records can also be found at the priority controlled intersections at Wellington Road, Goa Street and

Taurima Street.

Options which decrease the number of conflict points on the network would likely result in an improved

crash history. Grade-separated options were considered to remove conflict points and provide the

maximum safety benefit. The long four lane diagonal tunnel essentially removed all conflict points so

scored positively. Options which kept intersections at-grade provide a safety benefit from signalising the

priority intersections, but were not considered to provide the same level of benefit as the grade-separated

options due to the potential for rear-end crashes to continue.

Figure 5.8 – Safety assessment

Resilience

The existing Mt Victoria Tunnel and subsequent network are highly susceptible to blockage following an

accident or emergency. Network resilience is the measure of vulnerability and reliability of a network in

the event of a breakdown, incident, and emergency situation. The standard of the road, including the

width of the roadway, provision of shoulders and medians all adds to the resilience of a particular section

of road. The construction of new sections of road, and inclusion of local accessways add to the network

resilience by providing alternative routes for diverted traffic in the event of an emergency.

It has been assumed that both directions of traffic could be diverted down one of the tunnels in an

emergency situation and that grade separation at either end of the tunnel would not prohibit this

movement. The ‘Do Minimum’ option involves an increase in volumes of traffic through the corridor with

no alternative route provided and therefore scored negatively. Option 2 does not involve an additional

tunnel so no increase in resilience is provided. The majority of options include an alternative route and

hence lead to an improvement in network resilience. Traffic would be faced with additional conflict with

local traffic in Option 7 and therefore this option scored negatively.

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Operational - Safety


May 2011

Figure 5.9 – Network resilience assessment

5.4 Summary of assessment of transport criteria

The scores from each of the nine criteria have been summed to establish a total score in the two transport

related categories (Connectivity and Operational). These scores have been plotted in Figure 5.10. With

regards to option connectivity; tunnel alignment Options 1, 3, 6 and 8 stand out with strong

performances. Options involving a long diagonal tunnel (Options 4 and 5) score worst since connection to

Hataitai and Hataitai Park become restricted. In the Operational category, the significant difference comes

from the intersection treatment rather than tunnel alignment. At-grade intersection treatments generally

provide an inferior operation compared with grade-separated options.

Overall Options 3A, 3B, 6 and 8 with grade-separated intersection treatments scored highest in the

transport-related categories. Option 4 and Option 5 scored slightly lower. This is mainly due to decreased

connectivity. Interestingly, the at-grade solutions for Option 4 and Option 5 scored highest when

compared against other at-grade solutions.

Figure 5.10 Assessment scores for transport-related categories

0

1

2

3

40

-0

1-1

1-2

1-3

1-4

2-1

2-2

2-3

2-4

3A

-1

3A

-2

3A

-3

3A

-4

3B

-1

3B

-2

3B

-3

3B

-4

4A

-1

4A

-2

4A

-3

4B

-1

4B

-2

4B

-3

4C

-1

4C

-2

4C

-3

5A

-1

5A

-2

5A

-3

5B

-1

5B

-2

5B

-3

5C

-1

5C

-2

5C

-3

6-1

6-2

6-3

6-4

7-1

7-2

7-3

8-1

8-2

8-3

8-4

9-1

9-2

9-3

9-4

Sco

re

Options by code

Operational - Resilience


May 2011

6 Evaluation of intersection performance options

6.1 Approach

The key operational constraint in any transport network is always the intersections due to the capacities

being well below that of adjoining mid-block highway links. Consequently, the study has focused on

examining the performance of the current at-grade intersections (Goa/Ruahine, Wellington/Ruahine,

Kilbirnie/Wellington and Evans Bay/Cobham Drive) together with assessing their ability to accommodate

projected demand.

SIDRA has been used to examine the performance of each intersection flow. The current performance has

been evaluated using 2009 SATURN demand forecasts. It is acknowledged that SIDRA may not be the most

appropriate tool, given that many of the intersections are closely spaced. However, at the scoping stage it

is appropriate to make use of SIDRA in the knowledge that optimisation of intersection performance will

be examined in much more detail within the Scheme Assessment.

Intersection modelling has been carried out on key intersections within the study area to assess their

operation and ability to cater for the existing, and future 2026, traffic demands. In line with RoNS

objectives, an overall LOS (C/D) at intersections has been targeted.

6.2 Future year forecasts

Three alternative land use scenarios have been considered. These include:

1) WTSM 2026 projections – Basically this is the assumed Regional Council land use which assumes a

high public transport uptake and other given land use developments

2) Revised Land Use 2026(RLU) – this assumes that certain developments are guaranteed or about to

start construction – so there is a degree of certainty about their appearance

3) Enhanced Land Use 2026(ELU) - this really considers what is “out there” in terms of possibilities and

opportunities for the Eastern and Southern Suburbs. This assumes intensification in Lyall Bay and

Miramar, the Wellington Airport Master Plan, further development at Rongotai Business Park, Kilbirnie

growth spine eventuating together with the almost completed Indoor Community Sports Centre

(ICSC). Development of Shelley Bay would be included within this scenario. This produces a

maximum case demand which, when assessed against the capacity of the existing network, raises

problems in terms of congestion on key routes and forced rerouting.

The above land uses when translated through the Regional Council macro model (EMME2) and then local

CBD SATURN model produced some interesting results. The SATURN 2009 projections were commonly

shown to be at less than half of the predicted values for 2026 SATURN demand forecasts. Appendix I

provides a comparison of predicted traffic volumes between the different land use scenarios which have

been listed above. However, even between future year forecasts for the same design year there are


May 2011

significant differences. The ELU forecasts suggest demands between 5-90% higher than that arising from

the WTSM 2026 demand volumes.

Solely considering state highway traffic, the ELU demand forecasts exceed that of the 2009 modelled

network by between a factor between 1.37 and 3.07. The magnitude of such increases appears

questionable and consequently the project team adopted the WTSM 2026 demand forecast with the

intention of conducting sensitivity tests around RLU and ELU 2026 forecasts at the Scheme Assessment

stage to determine if the recommended alignments and intersection layouts would be able to

accommodate such extreme variation of demands.

A table showing the actual forecasted demands arising from the various land uses is presented within

Appendix I. The level of service values for mid-block sections of grade-separated arrangements have been

referenced from the Highway Capacity Manual and also Austroads Guide to Traffic Management.

The Wellington Transport Model (WTM) SATURN model was run using 2026 WTSM land use assumptions.

The WTM model includes the following assumptions:

• Wellington Strategic Transport Model (WTSM) development level. Growth matrices as per WTSM

predictions

• No change to fuel prices

• State Highway 2 Dowse to Petone upgrade (2016)

• Public Transport (PT) Rail extension to Waikanae (2016)

• PT Real time information (2016)

• SH1 Ngauranga to Aotea Quay Hard Shoulder Running (2016)

• Basin Reserve Grade Separation to Buckle Street (2016)

• Western Link Road stage 1 and 3 (2016)

• Peka Peka to Otaki expressway (2016)

• Terrace Tunnel duplication (2026)

• Mt Victoria Tunnel duplication (2026)

• Grenada to Petone 4 laning (2026)

• Transmission Gully (2026)

• Kapiti Expressway (2026)

• Otaki to Levin, Levin Bypass and north of Levin (2026).

SATURN Network – ‘Do Minimum’ includes:

• Manners Mall bus lanes

• Kent Terrace/Cambridge Terrace bus lanes

• Adelaide Road bus lanes

• Golden Mile speed reduction

• Signalised pedestrian crossing at Courtenay Place with bus priority

• Adelaide Road/John Street improvement

• Signalise Hanson Street/John Street intersection

• Signalise Constable Street/Owen Street intersection

• Signalise Constable Street/Coromandel Street intersection


May 2011

• Signalise Riddiford Street/Hospital Entrance

• Signalise Riddiford Street/South of Hospital pedestrian crossing

• Signalise Mulgrave Street/Aitken Street intersection

• Troy Street/Cobham Drive roundabout improvement

• Ruahine Street and Wellington Road 2 lanes each direction as per Opus PFR (Optimisation of State

Highway 1 –Ruahine Street to Kilbirnie Crescent Project Feasibility Report)

• Basin Reserve grade separation as per Option A

• Tory Street and Taranaki Street widening

• Inner City Bypass widening

• Terrace Tunnel Duplication in 2026 only.

SATURN Network – At grade option includes:

• Ruahine Street and Wellington Road at grade upgrade as per WTA developed

• Mt Victoria Tunnel duplication north side.

SATURN Network –Grade separated option includes:

• Ruahine Street and Wellington Road grade separated as per WTA developed

• Mt Victoria Tunnel duplication north side.

6.3 Existing situation

The existing situation SIDRA modelling is based on actual present layouts of the intersections within the

study length. 2009 traffic flows have been used which have been taken from the updated Wellington

SATURN Model. A summary of existing (2009) intersection performance has been included below in Table

6.1.

Table 6.1 Summary of existing intersection performance

Intersection Traffic demand Degree of

saturation

(DOS)

Average

Delay

(sec/veh)

LOS 95th percentile

back of queue

(m)

Cobham

Drive

AM peak 2009 demand 0.9 38 D 249

PM peak 2009 demand 0.9 31 C 201

Kilbirnie

Crescent

AM peak 2009 demand 1.0 56 E 375

PM peak 2009 demand 1.0 39 D 227

Wellington

Road

AM peak 2009 demand 1.1 44 n/a 121

PM peak 2009 demand 1.2 35 n/a 125

Goa Street AM peak 2009 demand 1.0 11 n/a 98

PM peak 2009 demand 1.0 9 n/a 86

Taurima AM peak 2009 demand 2.9 163 n/a 860


May 2011

Intersection Traffic demand Degree of

saturation

(DOS)

Average

Delay

(sec/veh)

LOS 95th percentile

back of queue

(m)

Street PM peak 2009 demand 2.1 67 n/a 481

SIDRA has been used to assess intersection performance. SIDRA only produces a LOS for signalised

intersections. At the priority intersections, certain approaches are given priority while others are

controlled by give way or stop signs. The LOS is different on each approach, therefore an intersection-wide

LOS is not appropriate.

Cobham Drive

At Cobham Drive, the degree of saturation (DOS), average delay and queue length are within acceptable

levels. The pedestrian crossings create long phases for the traffic on Evans Bay Parade and are unlikely to

be called each phase; and therefore represents a worst case through their inclusion within each cycle.

Kilbirnie Crescent

At Kilbirnie Crescent the intersection is at or approaching capacity. The Wellington Road western approach

is currently operating over capacity. As is the case for Cobham Drive, the pedestrian crossings cause long

phases for the Kilbirnie Crescent and Hamilton Road approaches.

Wellington Road

Wellington Road is operating above capacity on the Wellington Road western approach. The turning traffic

cannot find sufficient gaps within the state highway traffic to operate at a reasonable level during peak

hours.

Goa Street

The Goa Street intersection operates at capacity. The Goa Street and Hataitai Park access road battle to

find gaps in the state highway traffic. As a result, delays and queuing are experienced there.

Taurima Street

The right turn movement out of Taurima Street is severely over capacity. The significant amount of traffic

wanting to make this movement, coupled with a high opposing traffic flow, means traffic regularly queues

the length of Taurima Street. The through movements on Ruahine Street are operating well, according to

the intersection model, but in reality the merge movement between Taurima right turn traffic and west-

bound Ruahine Street traffic acts as a pinch point causing queues as the capacity of the merge is below

that of a single lane in the tunnel.


May 2011

6.4 ‘Do Nothing’ Scenario

A ‘Do Nothing’ case has been tested using 2026 WTSM traffic demands on the existing intersection

layouts. This scenario represents no physical changes to the intersection layouts, but a significant increase

in the traffic demands. The results are included in Table 6.2.

Table 6.2 Summary of ‘Do Nothing’ intersection performance

Do Nothing Traffic demand DOS

Average

Delay

(s) LOS

95th

percentile

back of

queue (m)

Cobham

Drive

AM peak 2026 demand 1.1

102 F 925

PM peak 2026 demand 1.4 219 F 1759

Kilbirnie

Crescent

AM peak 2026 demand 1.0 65 E 790

PM peak 2026 demand 1.2 114 F 1211

Wellington

Road

AM peak 2026 demand 5.7 7467 n/a 2726

PM peak 2026 demand 3.9 2930 n/a 3034

Goa Street

AM peak 2026 demand 6.2 16800 n/a 3549

PM peak 2026 demand 4.7 18700 n/a 6398

Taurima

Street

AM peak 2026 demand 4.4 498 n/a 4745

PM peak 2026 demand 2.4 372 n/a 4536

The operation of the existing intersections suffers significantly with the increase in traffic associated with

the 2026 WTSM traffic. The Kilbirnie Crescent and Cobham Drive handle the increased traffic best but still

operate at LOS F in the afternoon peak period with large associated delay and queuing. The priority

intersections of Wellington Road, Goa Street and Taurima Street all experience severe congestion. The side

road approaches cannot find sufficient gaps in the traffic and this leads to SIDRA predicting unrealistic

delay and queuing.

The models indicate excessive delay, particularly at the Wellington Road and Goa Street intersections.

Whilst this does indicate an operational problem with the priority intersection, it is unlikely vehicles will

experience an average delay to the level predicted. It is likely the intersection operates better than the

model predicts, with vehicles picking smaller gaps and driver courtesy allowing vehicles to turn onto the

state highway. Vehicles will reroute on alternative routes once the associated delay with a movement

becomes too large.


May 2011

6.5 ‘Do Minimum’ Scenario

The ‘Do Minimum’ scenario has been largely based on the Ruahine Street PFR produced by OPUS in June

2010. As described previously, the ‘Do Minimum’ option retains the use of the existing Mount Victoria

tunnel. The state highway widens to four lanes along both Ruahine and Wellington Road. Demands have

been taken from the 2026 WTSM forecast. A summary of ‘Do Minimum’ intersection performance has been

included below in Table 6.3.

Table 6.3 Summary of ‘Do Minimum’ intersection performance

‘Do

Minimum’

Intersection Traffic demand forecast DOS

Average

Delay

(secs/veh) LOS

95th

percentile

back of

queue (m)

Cobham

Drive

AM peak 2026 WTSM 1.1 102 F 925

PM peak 2026 WTSM 1.3 150 F 1308

Kilbirnie

Crescent

AM peak 2026 WTSM 1.0 69 E 816

PM peak 2026 WTSM 1.1 108 F 1194

Wellington

Road

AM peak 2026 WTSM 1.1 77 E 1197

PM peak 2026 WTSM 1.3 123 F 2147

Goa Street AM peak 2026 WTSM 1.2 255 F 1393

PM peak 2026 WTSM 1.7 389 F 2643

Taurima

Street

AM peak 2026 WTSM 0.8 6 n/a 0

PM peak 2026 WTSM 0.8 6 n/a 0

Cobham Drive

The substantial increase in through traffic causes the Wellington Road western approach to exceed

capacity. The heavy right turn from Cobham Drive to Evans Bay Parade (N) takes time away from the state

highway approaches on Wellington Road. Pedestrian crossings on Wellington Road and Cobham Drive

produce long phases for the Evans Bay Parade approaches.

Kilbirnie Crescent

The Wellington Road western approach is over capacity. Pedestrian crossing facilities across Wellington

Road add additional time to the phases of Kilbirnie Crescent and Hamilton Road, which takes time away

from the state highway.

Wellington Road


May 2011

The Ruahine Street approach exceeds its capacity. Long queues and delays are associated with this

movement. Pedestrian crossings across Ruahine Street cause increased phase time for the Wellington Road

southern approach which causes an imbalance in LOS between this approach and the state highway

approaches.

Goa Street

Operation of the Goa Street intersection is poor. The increase in through traffic and the Hataitai Park

approach operating every cycle causes large delays and queuing on the state highway. The length of

pedestrian crossings has a cumulative effect. The left turn from Goa Street is held back due to the

clearance of pedestrians on the crossing. Large queues occur on the state highway as a result of

signalising this intersection.

Taurima Street

The right and left turns from Taurima Street have been banned as part of the ‘Do Minimum’ scenario. The

only remaining turning movement is the left turn from the state highway into Taurima Street south. The

intersection operates with minimum delay and no queuing.

6.6 Optimised at-grade solution

An optimised at-grade solution has been developed in an attempt to achieve the desired LOS for the

corridor. The 2026 WTSM demands were used as input to the WTM SATURN model. The SATURN model

was coded with at-grade intersections to establish the demands for input into SIDRA. The following

modifications have been made to the ‘Do Minimum’ intersection layouts:

At the Cobham Drive/ Evans Bay Parade intersection:

� Additional lane added to Wellington Road approach.

At the Kilbirnie Crescent/Hamilton Road intersection

� Additional lane added to Wellington Road E and Wellington Road W approaches

� Bus priority lanes and bus pre-signals on Kilbirnie Crescent and Hamilton Road.

At the Wellington Road/Ruahine Street intersection:

� Additional lane to Wellington Road E approach

� Additional lane to Ruahine Street N approach

� Left turn lane on the Wellington Road E approach

� Additional right turn lane on the Wellington Road S approach.

At the Goa Street/Ruahine Street intersection:

� Additional lane to Ruahine Street N approach

� Additional lane to Ruahine Street S approach

� Additional left turn slip lane on the Ruahine Street N approach.


May 2011

In addition to the above changes, at-grade intersection layouts have been developed for tunnel alignments

Options 4 and 5. An at-grade intersection layout has been tested at the Wellington Road/Ruahine Street

for tunnel alignment Options 4 and 5 which involve either dual two lane (Option 4), or a single two lane

unidirectional tunnel (Option 5).

The upgraded at-grade intersections involve widening of the road reserve and will require significant land

take. Due to the close spacing of the intersections, it is important that the operation of the intersections is

assessed cumulatively. The SIDRA modelling provides only an indication at individual intersections of the

expected operation and does not reflect the possibility of optimising performance through signal

coordination. A summary of the optimised at-grade intersections results is given in Table 6.4.

Table 6.4 Summary of at-grade intersection performance

Optimised

At-grade

Traffic demand

forecast DOS

Average

Delay

(secs/veh) LOS

95th

percentile

back of

queue

(m)

Cobham

Drive

AM peak 2026 WTSM 0.9 33 C 462

PM peak 2026 WTSM 0.8 19 B 249

Kilbirnie

Crescent

AM peak 2026 WTSM 0.9 34 C 288

PM peak 2026 WTSM 1.0 42 D 405

Wellington

Street

AM peak 2026 WTSM 0.9 31 C 304

PM peak 2026 WTSM 0.9 30 C 456

Goa Street AM peak 2026 WTSM 0.8 26 C 285

PM peak 2026 WTSM 0.8 21 C 283

The operation of the intersections is within the desired LOS (C/D) at each of the intersections within the

study area. The Cobham Drive/Evans Bay Parade intersection operates well with a maximum degree of

saturation (DOS) of 0.9. The Kilbirnie Crescent intersection has a DOS of 1 during the PM peak period. This

DOS is associated with the Hamilton Road approach which is constrained by pedestrian crossing

movements. This will not have a significant effect on buses due to the bus priority lanes which are

proposed. The Wellington Road approach operates within capacity and to an acceptable LOS and DOS. Goa

Street operates at a DOS of 0.8 and LOS (C).

Queue lengths from the various intersections extend far enough to interfere with adjacent intersections.

The corridor needs to be assessed with coordinated signal timings to provide a more representative

prediction of operation.


May 2011

An at-grade intersection, at Wellington Road and Ruahine Street, for a four lane diagonal tunnel (Option 4-

1) operates at LOS (F). Large queues are associated with this intersection. Large queuing occurs on the

both state highway approaches, and queues would block back into the tunnel for 390m. An opportunity

exists to close the connection to Ruahine Street, which dramatically improves the performance of the

intersection. The intersection operates at a LOS (C) with queues reducing to 260m into the tunnel.

Queuing in the tunnel is undesirable from a traffic safety and fire life safety perspective.

The same at-grade intersection, for a two lane diagonal tunnel (Option 5-1) meets the LOS requirements

for the corridor. It experiences large queuing, but the queuing does not occur in the tunnel and could well

be reduced with signal co-ordination. Table 6.5 summarises the intersection performance of an at-grade

intersection for Options 4 and 5.

Table 6-5 Summary of at-grade intersection performance for diagonal tunnel alignments

(Options 4 & 5)

Optimised At-

grade

Traffic demand

forecast DOS

Average

Delay

(secs/veh) LOS

95th

percentile

back of

queue

(m)

Wellington Road for

Option 4-1

Wellington Road for

Option 5-1

Wellington Road for

Option 5-1 Ruahine

Street closed

AM peak 2026 WTSM 0.95 35.1 D 532

AM peak 2026 WTSM 1.13 92.6 F 960

AM peak 2026 WTSM 0.96 33.4 C 563


May 2011

6.7 Grade-separation

Interchange configurations have been investigated for several of the intersections within the corridor. The

2026 WTSM demands were used as input to the WTM SATURN model. The SATURN model was coded with

grade separated intersections (as per below) to establish the demands for input into SIDRA. Decisions have

been made on the basis of engineering feasibility and also existing topography. The following

assumptions have been made for modelling purposes:

Cobham Drive

� State highway is over local roads on a structure

� East-bound onramp is provided

� West-bound off ramp is provided

� Local roads provide access under the state highway structure.

Kilbirnie Crescent

� State highway is over locals roads on a structure

� West-bound onramp is provided

� East-bound off ramp is provided

� Local roads provide access under the state highway structure.

Wellington Road

� State highway is under the local roads in a trench

� West-bound onramp provided

� East-bound off ramp is provided.

Goa Street

� State highway is either over or under Goa Street

� West-bound onramp is provided

� West-bound service lane is provided.

There are alternative arrangements which could be considered at the various grade-separated

intersections. However, the above combination gives an appropriate representation of how to deal with

access needs and therefore has been adopted for evaluation purposes. Table 6.6 shows the SIDRA

intersection performance for each of the grade-separated intersections.


May 2011

Table 6.6: Summary of grade-separated intersection performance

Traffic demand DOS

Average

Delay

(s) LOS

95th

percentile

back of

queue

(m)

Cobham

Drive

AM peak 2026 WTSM 0.4 23 C 56

PM peak 2026 WTSM 0.5 24 C 63

Kilbirnie

Crescent

AM peak 2026 WTSM 0.6 16 B 30

PM peak 2026 WTSM 0.6 18 B 47

Wellington

Road

AM peak 2026 WTSM 0.6 12 B 75

PM peak 2026 WTSM 0.6 13 B 73

Goa Street AM peak 2026 WTSM 0.4 8 n/a 13

PM peak 2026 WTSM 0.3 8 n/a 9

Overall, all intersections perform well within their capacity with no major delay or queuing. There is

opportunity to reduce the footprint of the intersections at Kilbirnie Crescent and Cobham Drive, or

alternatively provide additional priority to other modes of travel. The LOS assessment describes an

appraisal of intersection performance at-grade without the influence of grade-separated traffic.

6.8 Summary of intersection modelling

Existing intersection performance (2009) In the present situation, Cobham Drive/Evans Bay Parade and Kilbirnie Crescent/Hamilton Road

intersections are operating at or close to capacity. The associated delays are within acceptable limits and

the LOS ranges (C-E).

The Wellington Road, Goa Street and Taurima Street are currently priority controlled. Under existing

conditions the state highway through traffic has no associated delay at these intersections. The crossing

and turning movements from Wellington Road, Goa Street and Taurima Street are all over capacity and

result in large queues and delays associated with these movements. This, in turn, has produced safety

issues for a number of these movements.

‘Do Minimum’ Scenario

The Cobham Drive/Evans Bay Parade and Kilbirnie Crescent /Hamilton Road intersections remain

essentially unchanged but experience a large increase in demand. This leads to LOS (F) at each of the

intersections during the afternoon peak.


May 2011

The introduction of traffic signals within a ‘Do Minimum’ has consequences at the previously priority

controlled intersections. The Wellington Road and Goa Street intersections both operate over capacity for

the state highway through movements causing large queues and significant delays. The operation of the

side roads (Goa Street and Wellington Road) shows an improvement in LOS from the introduction of

signals. Taurima Street experiences a significant increase in LOS due to the restriction of movements from

Taurima Street to Ruahine Street.

The ‘Do Minimum’ scenario represents a significant deterioration in operations over the existing traffic

conditions simply due to the significant increases in demand.

At-grade option

An at-grade solution has been developed to meet the project objectives for LOS through the corridor. The

optimised at-grade solution involves additional through lanes at the majority of the intersections. The

footprint of the at-grade solution is significant and is likely to require substantial land take outside of the

existing designation and slight realignment of the highway.

The upgraded signalised intersections achieve a LOS (D) or better in all cases. Some large queues still exist

from the intersections, but it is expected that these could be reduced through the co-ordination of the

series of signals.

At-grade options have been tested for the diagonal tunnel options (Options 4 and 5). Option 4A, a four

lane tunnel from Wellington to Paterson Street, has been modelled with an at-grade intersection. The

intersection meets the desired LOS, if connection to Ruahine Street is not provided, but queuing into the

tunnel portal remains a key issue. An at-grade intersection treatment is, therefore, not compatible with the

Option 4 tunnel alignment. An at-grade intersection for Option 5 achieves a LOS (D) and does not

experience problems with queuing into the tunnel portal, due to being unidirectional in a west-bound

direction.

Grade-separated option

A grade-separated solution has been developed to improve the LOS through the corridor. The grade

separation option involves the state highway either passing below local roads in a trench or passing over

on a structure. Due to the close spacing of the intersections, on and off ramps cannot be provided at every

intersection.

Signals are assumed at the Cobham Drive/Evans Bay Parade, Kilbirnie Crescent and Wellington Road

intersections. Goa Street would be priority controlled. All intersections operate well with a LOS (C/D) or

better. There will be opportunity to scale down some of the intersection treatments once the exact layout

of the scheme is established. This will see ramps provided to serve key or significant turning movements

only.

Overall the grade-separated option delivers the best LOS through the corridor.


May 2011

7 Discussion and recommendations for further assessment

The Scoping Report is the first stage of the phase covering the evaluation of potential alignments and

intersection upgrades associated with the duplication of the existing Mt Victoria Tunnel. As such, it is a

high level assessment. Further detail will be provided and will inform the process in order to form a short

list of options.

The duplication study is one of a series of RoNS projects identified for the Wellington Northern Corridor

between Wellington Airport and north of Levin. The recommendations for alignments to be carried forward

for further investigation within a Scheme Assessment Report have been made to be consistent with the

outcomes of the Ngauranga to Airport Study, while also fulfilling the individual objectives developed for

this specific RoNS project and neighbouring projects such as Basin Reserve.

Being an urban RoNS project, the design philosophy statement has to consider standards solely applicable

to urban areas. With a constraining designation in place along Ruahine Street and Wellington Road,

standards will have to be challenged and, at certain locations, possibly compromised. Such instances have

been highlighted and will need to be raised with the NZTA VAC. The existing horizontal and vertical

alignment constraints along the study section, which include both sub-standard radii of curvature and

gradients, have influenced recommendations regarding the future form of the state highway and its

connections with the local road network.

Ideally, the state highway should be brought up to expressway standard for a grade-separated option

which would imply a 70km/h speed limit. Given that geometric design speeds are generally 10km/h

higher than that of the imposed speed limit, an 80km/h environment should be reflected in the design. To

consistently provide a horizontal alignment to this standard would significantly affect the amount of land

take, particularly in the vicinity of Ruahine Street and Wellington Road.

If at-grade intersection improvements are proposed, the perception of the road will be more of an urban

road and so a 60km/h design speed could be contemplated. Some tunnel options may offer a possible

mixture of both speed limits (such as Option 5 which maintains the existing tunnel and Ruahine Street as

the east-bound carriageway) whilst proposing a new two lane west-bound alignment to a higher design

speed standard. Where at-grade intersections have been proposed, generally a speed limit of 60km/h has

been specified. Providing a higher design speed means larger curve radii are required which in turn means

more land is required. Similarly if a lower design speed of 50km/h were to be adopted, the impact on

surrounding land would reduce.

7.1 Issues and considerations

Other considerations which have a bearing on either the alignment of the duplicate tunnel or form of

intersection control include:


May 2011

Supporting economic development and improving productivity

This is the key rationale of the RoNS projects. Duplication of the Mount Victoria tunnel and upgrades along

the state highway will reduce congestion and increase the capacity of the corridor. The improvements will

support the development of activities in the eastern suburbs such as the airport, Rongatai Business Park

and Kilbirnie town centre. Overall, options for the corridor will seek to reduce travel time, increase trip

reliability and increase the proportion of the demand which is catered for on the state highway. The

attraction of traffic to the RoNS relieves Oriental Parade and Newtown providing opportunities for the

functions of these roads to change.

Improved access to the CBD from southern and eastern suburbs

The state highway corridor provides the main access route between the CBD and south/eastern suburbs.

Improving the capacity and operation of this corridor provides significant benefits to the movement of

goods and people between these key locations. Increasing the capacity of the corridor has a residual effect

of attracting a greater proportion of the demand, reducing trips which make use of local roads and

passenger transport corridors to move between the CBD and the southern and eastern suburbs.

Connectivity between, and to, local communities

Wherever possible, existing turning movements have been maintained unless they posed a safety issue or

the magnitude of a turning movement was deemed to be so minor that it could be neglected. With grade-

separation intersections, careful thought has been given to the provision and direction of ramps to ensure

that major turning movements are accommodated. The prohibition of movements or absence of ramps

can also influence the pattern of traffic movements between residential areas and the state highway

network. Specific attention was afforded to avoiding the establishment of “rat runs” and encouraging

longer local road trips prior to accessing the state highway.

Land take and local access needs

Satisfying access needs often conflicts with land take. Providing for grade separation and even at-grade

widening often means land outside of the designation is required. In a residential corridor this often

translates to taking private property and decisions have to made about the extent of land to be taken and

from which side of the road it should be taken from. In a high amenity area such as Hataitai Park, the

possible loss of town belt land can become a very emotive subject and this introduces a conflict between

taking town belt land against private land. Widening into reserve also introduces the issue of possible

ecological impacts arising from loss of vegetation.

Effect of transport infrastructure on community life

Ruahine Street and Wellington Road has always been recognised as a roading corridor with a designation

for potential widening in place. Consequently, any upgrade would not come as a surprise to local residents

in neighbouring communities. However, what will be unforeseen is the scale of the improvements.

Currently Ruahine Street and the majority of Wellington Road are two lanes wide. With an at-grade solution

this would be a minimum of four lanes. With grade separation, again four lanes would provide the

mainline, but in addition there will be ramps and possibly service lanes to provide for local access which

would create a much larger footprint. In addition, the presence of both trench and, in particular, elevated


May 2011

structures, could be regarded as visually intrusive and lead to additional noise, severance and reduction in

travel for local communities. The new corridor has to be considered in the light of its total effect on

neighbouring communities and the landscape and ecological qualities offered by Hataitai Park.

Value for money

Whilst some tunnel options may be perceived to reduce the environmental effects associated with highway

improvements, maintain connectivity and possibly remove the need for any land take, the cost of such

options should be assessed closely against other competing options in estimating value for money. The

trade off between providing additional tunnel length against the savings from not having to provide any

grade-separated infrastructure needs to be clearly understood. Overall cost and funding will be a major

issue for NZTA and so a sense of affordability has to be reflected in any option evaluation.

Provision for Public Transport

Whilst the existing public transport corridor on Moxham Avenue and through the Hataitai bus tunnel

remains as the preferred corridor option for buses, it is important the tunnel alignment does not preclude

the provision of a high quality passenger transport corridor in the future. The intersection upgrade

options at Kilbirnie Crescent/Wellington Road and along Moxham Avenue need to be consistent with

Wellington City’s long term plans to provide bus priority lanes along this corridor. Bus priority measures

are proposed at the Kilbirnie Crescent intersection which will ensure delay is minimised for bus services

crossing the State Highway.

Under the current modelling methodology no consideration has been given to the effect the options have

on public transport patronage. This is an important consideration and the WTSM model will be

interrogated in more detail during the SAR phase of the project.

7.2 Preferred tunnel alignments

Based on the results of the option evaluation conducted on duplicate tunnel alignments, Options 3A, 3B,

5A and 5B appear to be the most favourable options to take forward to the Scheme Assessment stage. (All

other options have been addressed and reported on in terms of their ability to satisfy project objectives.)

Options 3A (tunnel to the north) and 3B (tunnel to the south)

These options support the functionality of the existing corridor. The problems with these alignments, and

indeed any of the options which involve four laning Ruahine Street and Wellington Road, all revolve around

the upgrade of intersections. The Wellington Road/Ruahine Street intersection and the tight horizontal

curve linking the two elements of the state highway, means that any curve realignment will involve land

take of private property. The higher the design speed, the more intrusive the land take. This intersection

while not imposing the maximum demands, is particularly difficult to address with an at-grade solution

given its existing restricted horizontal curve radius. Even to upgrade to a 50km/h design speed implies a

significant land take.

Options 4A and 4B


May 2011

A twin two lane tunnel with the eastern portal either prior to Ruahine Street/Wellington Road or Kilbirnie

Crescent/Hamilton Road appears attractive at first glance as they remove all the issues associated with

widening Ruahine Street which effectively becomes a local road. However, the queues likely to result at the

intersection immediately east of the portal could well extend back into the tunnel. This has the potential

to become a major safety issue and is undesirable as it does not meet fire life safety standards. The other

major disadvantage is the high cost associated with a wide and lengthy tunnel bore. Tunnel portals east of

Kilbirnie Crescent have not been supported for further investigation due to fear of flooding.

Options 5A and 5B

A two lane uni-directional west-bound tunnel with possible portal locations as above, would be

considerably cheaper than a four lane two-directional tunnel and would also remove the issue of queuing

east-bound traffic exiting the tunnel. Ruahine Street would become the east-bound state highway with

traffic levels much reduced over that currently experienced, although Options 4A and 4B would produce

even more diminished flows.

For Hataitai residents travelling by private vehicle, the CBD-bound journey requires a more circuitous

journey with the loss of connection via Taurima Street and Goa Street to the state highway. Trips are likely

to involve accessing the highway via Hamilton Road or by a connection at Ruahine Street/Wellington Road.

7.3 Intersection appraisal

The general expectation of intersection upgrades is that existing priority intersections would become

traffic signal-controlled. This is in line with the conventional hierarchical improvements which extend from

priority to traffic signals/roundabouts to grade separation. Such improvements will be designed to a

posted speed limit of 60 km/h which is proposed within the Design Philosophy Statement, and which

reflects an incremental increase in speed limits from 50km/h at Basin Reserve to 70km/h east of Cobham

Drive.

However, the challenge to produce an at-grade solution becomes evident through reference to Figure 7-1

extracted from the HCM. If the average daily flow along Ruahine Street is plotted against the side road

flows at Taurima Street, Goa Street, Wellington Road, Kilbirnie Crescent and Evans Bay Parade, all, with the

exception of Goa Street, would justify grade separation at 2009 levels.


May 2011

Figure 7-1: Type of junction appropriate for different traffic flows (source: HCM6)

Four laning Wellington Road and Ruahine Street with subsequent additional widening at the above

intersections, to provide for Options 3A and 3B, fail to meet the RoNS level of service requirement over the

entire study length. Indeed all show excessive congestion with lengthy delays and long queues. Widening

to three lanes in each direction deals with the level of service deficiencies at all intersections satisfying the

minimum standard of LOS(D). Whilst the two lanes in each direction for the respective tunnel alignments

operate efficiently, the intersections impose considerable problems for both side road and state highway

traffic alike. The at-grade solution being proposed offers a combination of two and three lane approaches

with road widening at intersections.

The question of acceptability and scale of development now need to be considered. Two lanes at-grade

would appear to be acceptable but fail to work operationally at 2026. Three lanes in each direction with

predominantly traffic signals appears to work reasonably well but immediately raises the question of

acceptability in terms of footprint for a six lane highway against even a dual grade-separated treatment.

The compromise of a two/three lane arrangement may prove more sympathetic.

6 Transport Research Board. Highway Capacity Manual. Roads in Urban Areas


May 2011

Ideally, in view of land take and footprint, and to limit the scale of the roading corridor to two lanes in

each direction, grade-separation was considered. It became evident from the existing topography that the

following arrangements were the most appropriate:

� Goa Street/Wellington Road – state highway either elevated or at-grade (preferably local road over)

� Wellington Road/Ruahine Street – state highway in trench (local road over)

� Kilbirnie Crescent/Wellington Road – state highway elevated

� Evans Bay Parade/Cobham Drive – state highway elevated.

The next issue was to examine the need for all side road movements to be retained or provided and

identify which movements could not be physically accommodated. This resulted in the most optimal

arrangement for grade- separation as shown in Appendix K (Figure 0-3 andFigure 0-4). There are

alternative arrangements for dealing with on ramps for Kilbirnie Crescent and Goa Street which will be

taken forward for further investigation. The affected movements which require additional investigation

include the CBD west-bound movement from Taurima Street, the left turn from Wellington Road south at

the Wellington Road/Ruahine Street intersection, and the off and on ramps at Goa Street for east-bound

traffic.

7.4 Next steps

The Scheme Assessment Report will be the stage at which detailed examination of tunnel options and

intersections upgrades needs to be undertaken. This will require results, model output and evaluation

criteria which clearly point to a definitive solution and which can be supported by robust and evidence

based outcomes. All data provided within any report will need to be defendable.

In terms of land use and the demand which has to be accommodated by the new network or road

arrangement, the revised land use (RLU) will be probably utilised which represents a midway assessment

between WTSM and the enhanced land use (ELU). It is also likely that the Basin Reserve Project Team may

have to perform a sensitivity test around this new land use.

The WTA Project Team is also aware of the on-going upgrade of the SATURN model and the likelihood that

this will be available for use at Scheme Assessment stage. It is assumed that any 2009 model will be

replaced by a new 2010 SATURN upgrade once it has been peer reviewed and approved.

It is intended to clearly report upon the differences in operational performance of the ‘Do Nothing’, ‘Do

Minimum’ and potential at-grade and grade-separated options to build upon the initial investigatory work

undertaken within this scoping report. This is also likely to include a study of how traffic signals, provided

within both ‘Do Minimum’ and at-grade solutions, can be co-ordinated and optimised to allow for more

efficient traffic flow. Use will also be made of the Opus micro simulation model to test the various options

and address concerns over build-up of queues at intersections and on both on and off ramps.

There are also a few options relating particularly to on ramps which require further examination as

alternative connectivity locations remain to be resolved and finalised.


May 2011

During the scoping stage, it has been recognised that alternative at-grade and grade separation

arrangements at Kilbirnie Crescent and Evans Bay Parade are possible with the aim of minimising the

number of ramps and, in doing so, reducing the visual effect and footprint of the new imposing

infrastructure. This will be subject of further sensitivity tests. This has an effect on traffic circulation on

neighbouring approach roads. Both one-way and two-way traffic arrangements will require examination for

the roads passing around the perimeter of Kilbirnie Park.

There are also implications around the effects of local traffic management issues and, in particular, some

clear understanding of how the local Hataitai network deals with both at-grade and grade-separated

options. In several cases, there may be the need for the local street network to accommodate additional

flows arising from particular options. These need to be understood in terms of access to and from the

state highway network. This should allow for conventional commuter daily movements via local road

connections and the movements between neighbouring communities. A deeper understanding of

origin/destination movements for adjacent communities will be required to ensure that ramps are

correctly located and fulfil their intended purpose.

The importance of the public transport spine from Kilbirnie through Hataitai and then the bus tunnel to

the CBD will not be overlooked during the further development of options. Every opportunity will be

sought to improve the attractiveness and reliability of public transport especially in the form of bus lanes

and priority measures at intersections.

Costs are clearly influential in the minds of the client and also the project team. Value for money has to be

reinforced as a clear objective and this differentiator has to be addressed within the course of the study

report. At Scheme Assessment stage the costs of the various options will need to be clarified and fed into

the evaluation process. They will reflect increased confidence in their projected figures above that initially

adopted at the Scoping Report stage.

There are still major debates and opinions around whether at-grade or grade-separation solutions are

preferable. If the entire corridor and beyond (Mt Victoria Tunnel to Terrace Tunnel) is progressed then all

options need to be future-proofed to ensure that any proposal can upgraded at a future date to provide a

fully grade-separated corridor treatment.

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