Black Spot Feasibility Study Hindmarsh Drive / Eggleston Crescent Intersection

Roads ACT 27 March 2012 Document No. 60240482RPTRA003_2

Black Spot Feasibility Study Hindmarsh Drive / Eggleston Crescent Intersection

AECOM Black Spot Feasibility Study - Hindmarsh Drive / Eggleston Crescent Intersection

P:\CBR\60240482_Blackspot_Feas\8. Issued Docs\8.1 Reports\60240482RPTRA003_2 Hindmarsh Dr _ Eggleston Cr .docx Revision 2 - 27 March 2012

Black Spot Feasibility Study Hindmarsh Drive / Eggleston Crescent Intersection

Prepared for

Roads ACT

Prepared by AECOM Australia Pty Ltd Level 2, 60 Marcus Clarke Street, Canberra ACT 2600, Australia T +61 2 6201 3000 F +61 2 6201 3099 www.aecom.com ABN 20 093 846 925

27 March 2012

60240482

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Quality Information Document Black Spot Feasibility Study

Ref 60240482

Date 27 March 2012

Prepared by Leigh Palmer, Margo Aziz & Michael Jollon

Reviewed by Tim Rampton

Revision History

Revision Revision Date Details

Authorised

Name/Position Signature

1 16-Mar-2011 Draft Report Tom Brimson Technical Director

2 27-Mar-2012 Final Report Tom Brimson Technical Director



Table of Contents Executive Summary i 1.0 Introduction 1

1.1 Overall Objective 2 1.2 Project Tasks 2

2.0 Comprehensive Crash Analysis 3 2.1 Crash Data Analysis 3 2.2 Crash diagram 6 2.3 Traffic Characteristics 7

2.3.1 Intersection / Road Geometry 7 2.3.2 Traffic Volume 8 2.3.3 Traffic Speed 8 2.3.4 Public Transport 8 2.3.5 Bicycles and Pedestrians 9 2.3.6 Land Use 9

3.0 Site inspection 10 4.0 Development of Remedial Measures 11

4.1 Objectives 11 4.2 Constraints 11 4.3 Opportunities for Remedial Measures 11 4.4 Opportunities to Improve Existing Deficiencies 11

5.0 Improvement Options 12 5.1 Option 1 a – Reduce Hindmarsh Drive to Two through Lanes at the Intersection 12

5.1.1 Physical Description 12 5.1.2 Cost 12 5.1.3 Potential Crash Reduction 12

5.2 Option 1 b – Reduce Hindmarsh Drive to Two through Lanes at Eggleston Crescent and at Launceston Street 13 5.2.1 Physical Description 13 5.2.2 Cost 14 5.2.3 Potential Crash Reduction 14

5.3 Option 2 – Median Closure on Hindmarsh Drive 14 5.3.1 Physical Description 14 5.3.2 Cost 15 5.3.3 Potential Crash Reduction 15

5.4 Option 3 –Close Intersection and Signalise Hindmarsh Drive / Launceston Street / McDonald Street Intersection 15 5.4.1 Physical Description 15 5.4.2 Cost 16 5.4.3 Potential Crash Reduction 16

6.0 Analysis and Recommendation 17 6.1 Options Comparison 17

6.1.1 Expected Crash Reductions 17 6.1.2 Economic Analysis 17

6.2 Improvements to Correct Existing Deficiencies 21 6.2.1 Relocate Give – Way Warning Sign on Northbound Eggleston Crescent 22 6.2.2 Existing Deficiencies Summary 22

6.3 Recommendation 22 Appendix A

Crash Data for the ACT (2007 - 2010) A

List of Tables

Table 1 Number of Crashes by severity and year 3 Table 2 Crash Factor Matrix 4 Table 3 Major Crash Types 5



Table 4 Estimated Percentage Reduction in crashes from Option 1 13 Table 5 Estimated Percentage Reduction in crashes from Option 2 15 Table 6 Estimated Percentage Reduction in crashes from Option 1 16 Table 7 Crash Costs in the Australian Capital Territory 17 Table 8 Crash Cost by Severity in the Australian Capital Territory 18 Table 9 Benefit/Cost Analysis for Single-Location Options 19 Table 10 Benefit/Cost Analysis for Two-Location Options 20 Table 11 Summary of Benefit to Cost Analysis 21 Table 12 Level of Risk 21 Table 13 Existing Deficiency Summary 22

List of Figures

Figure 1 Hindmarsh Drive / Eggleston Crescent Intersection 1 Figure 2 Crash Diagram 6 Figure 3 Hindmarsh Drive / Eggleston Crescent Intersection 7 Figure 4 ACTION Weekday Bus Service 8 Figure 5 Walking and Cycling Facilities at Hindmarsh Drive / Eggleston Crescent Intersection 9 Figure 6 Option 1 a – Lane reduction on Hindmarsh Drive 12 Figure 7 Option 1 b – Lane reduction on Hindmarsh Drive 13 Figure 8 Option 2 – Median Closure on Hindmarsh Drive at the Intersection 14 Figure 9 Option 3 – Intersection closure and signalisation of Hindmarsh Drive / Launceston Street

/ McDonald Street intersection 16



i

Executive Summary Background

Roads ACT have commissioned AECOM Australia Pty Ltd to undertake 7 black spot crash studies in the ACT. These studies included 4 intersections and 3 midblock locations. These investigations examined the most recently available five year crash history for each site to ascertain the contributory factors and develop remedial measures for each site.

The ACT Road Safety Strategy for 2011 – 2020 aims to meet a national goal of at least a 30% reduction in fatalities and serious injuries by 2020. Providing safe roads and roadsides is one component of an integrated approach to meet this goal. Our study will provide the ACT Government with a range of cost effective and safe upgrade options which will allow for informed recommendations to be made. The aim of the project is to

Identify the contributory factors associated with crashes at the site.

Identify any features seen during site inspections, which may adversely contribute to crashes at this location.

Develop potential remedial measures.

Evaluate the effectiveness of these remedial measures.

Select and recommend the most appropriate measure(s).

This report focuses on the intersection of Hindmarsh Drive and Eggleston Crescent.

Crash Analysis

The recorded crashes were obtained from Roads ACT for the five year period from January 2006 until December 2010.

The records indicate that 32 crashes have occurred at the intersection of Hindmarsh Drive and Eggleston Crescent. Of these crashes, 4 were injury crashes and the rest were property damage only crashes.

This intersection experienced an annual average of 6.4 crashes. The range has varied from 5 to 9 crashes per annum. The greatest number of crashes was rear-end collisions.

Of the 32 crashes, 4 (12.5%) were casualty crashes. The ACT annual average casualty rate at a Give Way control over the 4 year period 2007 – 2010 was 6.4%. In respect to casualties, this intersection fares worse than the average Give Way control (details outlined in Appendix A).

Options Analysis

As a result of the crash analysis and a review of existing deficiencies found on site, the following improvement options were assessed:

- Option 1 a – Reduce Hindmarsh Drive to two through lanes at the intersection.

- Option 1 b – Reduce Hindmarsh Drive to two through lanes at Eggleston Crescent and at Launceston Street

- Option 2 – Median closure on Hindmarsh Drive

- Option 3 – Close the intersection and install new signalised cross intersection at Hindmarsh Drive / Launceston Street / McDonald Street.

An obscured Give-Way Warning sign on northbound Eggleston Crescent was identified as an existing deficiency.

Each option was allocated an indicative implementation cost and assessed for potential crash reduction savings. The results of the cost benefit analysis are summarised in Table A.



ii

Table A Summary of Benefit to Cost Analysis

OPTION Treatment Cost B/C Ratio NPV

OPTION 1 a Lane reduction of Hindmarsh Drive at the Eggleston Crescent $94,000 2.66 $210,765

OPTION 1 b Lane reduction of Hindmarsh Drive at the Eggleston Crescent and Launceston Street $230,000 2.09 $337,305

OPTION 2 Median closure with let turn deceleration / acceleration lanes $122,000 3.54 $419,354

OPTION 3

Closure of the subject intersection with installing new signalised intersection at Hindmarsh Dr. / Launceston St. / MacDonald St $370,000 0.58 -$209,491

The benefit to cost analysis indicates that each option yields benefits in excess of its costs. Option 1 a and 1 b, reducing through lanes, and Eggleston Crescent and possibly at Launceston Street are both viable options. Option 2, median closure, is not viable because of the effect it would have on Chifley residents. Options 3, road closure and signalisation, is effective, however high costs keep it from meeting the black spot program economic criteria.

The potential crash risk of the identified existing deficiency was evaluated using road safety audit principles. The results are summarised in Table B.

Table B Existing Deficiency Summary

DEFICIENCY RISK TREATMENT COST ESTIMATE

Hidden Give-Way Warning Sign Low Relocate Sign $500

Recommendation

Option 1 b, reducing through lanes at Eggleston Crescent and Launceston Street is recommended because it offers effective crash reductions for two intersections, and it maintains consistency and driver expectations.

It is worth noting that the Austroads Guide to Traffic Management (Part 3) states that the maximum carrying capacity of a lane to maintain a Level of Service (LOS)‘C’ is 1280 veh/hr/lane. The current peak hour volume on this section of Hindmarsh Drive is approximately 2,300 per hour in the peak direction (across three lanes). With the proposed reduction in traffic lanes from three to two between Eggleston Crescent and Launceston Street, this would equate to around 1,200 veh/hr/lane – within the LOS C criteria. However, slight delays are likely to occur at the merge points of the corridor, so careful consideration will need to be given as to their location.

The Give –Way warning sign on Eggleston crescent should be relocated to improve intersection legibility and reinforce priority.



1

1.0 Introduction Roads ACT have commissioned AECOM Australia Pty Ltd to undertake 7 black spot crash studies in the ACT and this included 4 intersections and 3 midblock sections. These investigations examined the most recently available five year crash history for each site to ascertain the contributory factors and develop remedial measures for each site.

The following sites were examined.

Intersections

1. Sandford Street / Gungahlin Drive

2. Athllon Drive / Fincham Crescent

3. Hindmarsh Drive / Eggleston Crescent

4. Kingsford Smith / Spalding Street

Midblock road sections 5. Monaro Highway – between Hindmarsh Drive and Lanyon Drive 6. Challis Street – between Cape Street and Morphett Street 7. Aikman Drive – between Emu Bank and Townsend Place

This report is one of seven studies and presents the findings and recommendations for the intersection of Hindmarsh Drive and Eggleston Crescent. This intersection is located in Chifley. The intersection is shown in Figure 1.

Figure 1 Hindmarsh Drive / Eggleston Crescent Intersection

Source; ACTMAPi - ACT Government online interactive maps



2

1.1 Overall Objective The ACT Road Safety Strategy for 2011 – 2020 aims to meet a national goal of at least a 30% reduction in fatalities and serious injuries by 2020. Providing safe roads and roadsides is one component of an integrated approach to meet this goal. Our study will provide the ACT Government with a range of cost effective and safe upgrade options which will allow for informed recommendations to be made. The aim of the project is to:

Identify the contributory factors associated with crashes at the site

Identify any features seen during site inspections, which may adversely contribute to crashes at this location

Develop potential remedial measures

Evaluate the effectiveness of these remedial measures

Select and recommend the most appropriate measure(s)

1.2 Project Tasks The crash investigations include the following tasks:

A comprehensive crash analysis using Roads ACT crash data base for the five year period from January 2006 until December 2010

Development of a crash matrix

Development of a crash diagram

Development of potential countermeasures

Assessment of those countermeasures

Selection and recommendation of the preferred countermeasure

Summary and conclusions



3

2.0 Comprehensive Crash Analysis

2.1 Crash Data Analysis The recorded crashes were obtained from Roads ACT for the five year period from January 2006 until December 2010. These crashes were reviewed to identify any crash patterns and trends and also assist in the understanding of the contributory causes of the crashes. Ambiguities and coding errors were discovered in some of the crash data. These records were reinterpreted using engineering judgement and consideration of the crash patterns in the intersection.

The records indicate that 32 crashes have occurred at the intersection of Hindmarsh Drive and Eggleston Crescent. Of these crashes, 4 were injury crashes and the rest were property damage only crashes as shown in Table 1.

Table 1 Number of Crashes by severity and year

Severity 2006 2007 2008 2009 2010 Total

Fatal

Admitted to Hospital

Received Medical Treatment

1 1 1 1 4

Property Damage Only

5 4 8 4 7 28

Total 5 5 9 5 8 32

A crash factor matrix has been prepared and is shown in Table 2.



4

Table 2 Crash Factor Matrix

DCA Code On Street Key

Direction

Year of Crash

Total

Other Direction Surface Light Conditions Type of Day

Weekday Peak Period

2006

2007

2008

2009

2010

Nor

th

East

Sout

h

Wes

t

Dry

Wet

Day

Dar

k

Publ

ic

Hol

iday

Sc

hool

H

olid

ay

Wee

k -

ends

W

eek

- da

ys

104

Hindmarsh Dr WB 1 1 2 2 2 1 1 1 1

107

Hindmarsh Dr WB 1 1 2 4 4 3 1 3 1 1 3 1

202

Hindmarsh Dr WB 2 1 1 4 4 4 3 1 1 3

301

Hindmarsh Dr WB 1 3 4 4 3 1 3 1 1 3 2

Eggleston Cres NB 2 1 3 3 3 3 1 1 1 1

302

Hindmarsh Dr WB 1 1 1 1 1 1

Eggleston Cres NB 1 1 3 2 1 8 8 8 5 3 2 6 3

303

Hindmarsh Dr EB 1 1 2 2 2 2 2

Eggleston Cres NB 1 1 1 1 1 1

304

Hindmarsh Dr WB 1 1 1 1 1 1 1

306

Hindmarsh Dr WB 1 1 1 1 1 1 1

804

Hindmarsh Dr WB 1 1 1 1 1

Total 5 5 9 5 8 32 18 6 0 7 30 2 25 7 0 4 7 21 9



5

Table 3 Major Crash Types

Description and DCA

Code

Adjacent Approach (101-109)

Head – on (201)

Opposing turns (202-

206)

Rear-end (301-304)

Lane change

(305-307)

Parallel lanes – turning

(308,309)

Vehicle hits Pedestrian (001-003)

Loss of control, L or R turns (706,707)

Hit parked / parking vehicle

(601,401,402

Other

Total

Total 6 4 20 1 1 32



6

Analysis of crash details reveals the following:

- 20 crashes out of total 32 were rear-end crashes.

- 6 crashes were adjacent approach crashes and 4 crashes involved opposing turns

- 21 crashes occurred during a weekday, 9 were in peak hours.

- The majority of crashes occurred in good weather and during daylight.

- There were zero crashes involving pedestrians.

2.2 Crash diagram

Figure 2 Crash Diagram

: Injury

Analysis of crash diagram reveals the following:

- 2 injury crashes involved adjacent approach vehicles and the other two involved opposing turn vehicles.

- 12 crashes out of total 20 rear-end crashes involved northbound traffic on Eggleston Crescent.

- The majority of crashes involved the left turn movements out of Eggleston Crescent and the right turn movements into Eggleston Crescent.



7

2.3 Traffic Characteristics 2.3.1 Intersection / Road Geometry

Hindmarsh Drive

Hindmarsh Drive is an arterial road running east-west across the southern suburbs of the ACT. It connects Weston Creek to the Woden Valley, Narrabundah and Fyshwick. Hindmarsh Drive is a 6 lane divided carriage way at its intersection with Eggleston Crescent. The pavement width at its intersection with Eggleston Crescent is about 11 metres on each carriageway.

Eggleston Crescent

Eggleston Crescent is a major collector road in Chifley connecting Hindmarsh Drive to Melrose Drive. It is a two lane undivided road. At its intersection with Hindmarsh Drive the pavement width is about 16 metres.

Intersection

The intersection is a seagull arrangement controlled by a give way sign on Eggleston Crescent. Right turn movements out of Eggleston Crescent have a dedicated lane on Eggleston Crescent but have no acceleration lane on Hindmarsh Drive. Right turn movements out of Hindmarsh Drive have a turn lane on Hindmarsh Drive. Slip lanes are provided for left turns as shown in Figure 3.

Figure 3 Hindmarsh Drive / Eggleston Crescent Intersection

Source; ACTMAPi - ACT Government online interactive maps



8

2.3.2 Traffic Volume

No traffic counts near this intersection were discovered. Traffic counts on Hindmarsh Drive east of Melrose Drive were reported in Roads ACT’s traffic volume report for the period 2005 – 2007. These counts indicate average volumes of 23,000 weekday vehicles. Midblock peak hour volumes on Hindmarsh Drive were found to be approximately 2,300 veh/hr in the peak direction (Eastbound in the AM and Westbound in the PM)

No traffic counts were found for Eggleston Crescent.

2.3.3 Traffic Speed

The signposted speed limits on the roads approaching the intersection are as follows:

- 80 km/h on Hindmarsh Drive

- 60 km/h on Eggleston Crescent

Traffic speed data was not available for this report.

2.3.4 Public Transport

Many Action weekday bus services travel through the intersection go to and from the Woden Bus Interchange. Hindmarsh Drive carries routes 25, 75, 227, 26, 62,162, 23, 24 and Xpresso 749. Eggleston Crescent carries routes 23 and 24 (both routes turning through the intersection). There are no bus stops located near the intersection. The nearest bus stop is located on Eggleston Crescent about 270 metres south as shown in Figure 4.

Figure 4 ACTION Weekday Bus Service



9

2.3.5 Bicycles and Pedestrians

On street cycle lanes and a shared use path are provided on Hindmarsh Drive. Foot paths are provided on both Hindmarsh Drive and Eggleston Crescent as shown in Figure 5.

Figure 5 Walking and Cycling Facilities at Hindmarsh Drive / Eggleston Crescent Intersection

Source: ACT Walking and Cycling Map

Legend: On road Cycle Lane, Shared Path, Foot path

2.3.6 Land Use

There is no direct residential access on Hindmarsh Drive. Eggleston Crescent provides direct access to residential properties.



10

3.0 Site inspection A weekday site inspection was undertaken on Tuesday, 31 January 2012 at 4.00 pm. The following observations were noted:

- The majority of turning movements at the intersection are right turn movements into Eggleston Crescent and left turn movements out of Eggleston Crescent (in the PM)

- Many drivers turning right into Eggleston Crescent use Eggleston Crescent to connect to other Woden Valley suburbs via Macfarland Crescent.

- The intersection warning sign (Give Way ahead) on Eggleston Crescent is hidden by a tree; however the intersection is clearly visible.

- Sight distance is adequate at the intersection.

- A long queue on the left turn movement out of Eggleston Crescent was observed.

- There was little to no queuing on right turn movement out of Eggleston Crescent.

- Drivers turning right into and out of Eggleston Crescent may misjudge the gap crossing three lanes which are travelling at 80 km/h.

- The sight lines of vehicles in the left turn lane out of Eggleston Crescent can be obscured by vehicles turning right. This may result in hesitation and may be a factor in rear-end crashes.

The Give Way warning sign is obscured by a street tree.

The largest turning movements are left turns out and right turns into Eggleston Crescent.

A long queue develops in left turn bay out of Eggleston Crescent.

The right turn out of Eggleston Crescent is not very heavy.



11

4.0 Development of Remedial Measures

4.1 Objectives The key objective in developing safety measures is to reduce the number and/or severity of crashes. The reduction in severity or total trauma is often best done by reducing the potential for right angle crashes.

4.2 Constraints - Hindmarsh Drive is a heavily trafficked arterial road connecting Weston Creek through to Fyshwick.

It has three lanes in either direction

It has an 80km/h speed limit

- Eggleston Crescent is a heavily trafficked major collector road providing access to Chifley and direct property access to houses.

- The surrounding land is established residential neighbourhoods. The solution should remain within the road reserve. (Hindmarsh Drive reserve is approximately 57 metres.)

4.3 Opportunities for Remedial Measures The key type of crash at Hindmarsh Drive / Eggleston Crescent is rear-end crashes (60%); however injuries at the intersection involved adjacent approach crashes and opposing turn crashes. The following remedial measures were considered as possible opportunities to reduce the number and/or severity of these key crashes:

- Reduce Hindmarsh Drive to two through lanes at the intersection.

- Close the median on Hindmarsh Drive at the subject intersection.

- Close the subject intersection and install cross signalised intersection at Hindmarsh Drive / Launceston Street / McDonald Street.

4.4 Opportunities to Improve Existing Deficiencies On northbound Eggleston Crescent, a warning sign is hidden by a tree. This sign should be relocated to a position before the tree.



12

5.0 Improvement Options

5.1 Option 1 a – Reduce Hindmarsh Drive to Two through Lanes at the Intersection

5.1.1 Physical Description

This option provides a lane reduction on westbound Hindmarsh Drive by converting the left hand through lane to a left turn deceleration lane before Eggleston Crescent and a left turn acceleration lane out of Eggleston Crescent. This will simplify gap identification for drivers turning right in or right out of Eggleston Crescent as the crossing will be reduced to two lanes as shown in Figure 6. The proposed treatment would reduce the adjacent approach crashes as well as the rear-end crashes experienced turning left out of Eggleston Crescent. (Left and centre through lanes on Hindmarsh Drive should be merged before the intersection to avoid a trap lane condition.)

Figure 6 Option 1 a – Lane reduction on Hindmarsh Drive

5.1.2 Cost

The estimate of probable cost to install this treatment is $94,000 excluding GST. No detailed design or assessment of the existing hardware or underground services has been undertaken.

5.1.3 Potential Crash Reduction

Lane reduction of Hindmarsh Drive at the intersection is expected to have the following impact on crash frequency:



13

Table 4 Estimated Percentage Reduction in crashes from Option 1

Target Crash Assumed Crash Reduction Reference

Adjacent approach crash (crash codes 101-109)

10% RTA 2005, Accident Reduction Guide Part 1, table C1 Page 70

Opposing turn (crash codes 202-206)


Rear-end crash (crash codes 301-304)


Lane change crash (crash codes 305 – 307)


5.2 Option 1 b – Reduce Hindmarsh Drive to Two through Lanes at Eggleston Crescent and at Launceston Street


AECOM completed a previous black spot feasibility study at the Hindmarsh Drive / Launceston Street intersection for which none of the considered measures generated benefits greater than costs. The Hindmarsh Drive / Launceston Street intersection is located about 400 m west from the subject intersection. This treatment takes into consideration the two black spot sites. This treatment would include:

- lane reduction and deceleration and acceleration lanes on westbound Hindmarsh Drive at Eggleston Crescent (as in Option 1 a)

- similar lane reduction and auxiliary lanes in eastbound Hindmarsh Drive at Launceston Street

Similar lane reductions have been at unsignalised t-intersections on Melrose Drive in Phillip. The proposed treatment would reduce the total number of key crashes occurring at both intersections of Hindmarsh Drive / Eggleston Crescent and Hindmarsh Drive / Launceston Street. Added benefits of treating the two black spot locations include reinforcing driver expectation by installing similar treatments for adjacent similar intersections, and capitalising on mobilisation costs.

Figure 7 Option 1 b – Lane reduction on Hindmarsh Drive

It is worth noting that the Austroads Guide to Traffic Management (Part 3) states that the maximum carrying capacity of a lane to maintain a Level of Service (LOS)‘C’ is 1280 veh/hr/lane. The current peak hour volume on this section of Hindmarsh Drive is approximately 2,300 per hour in the peak direction (across three lanes). With the proposed reduction in traffic lanes from three to two between Eggleston Crescent and Launceston Street, this



14

would equate to around 1,200 veh/hr/lane – within the LOS C criteria. However, slight delays are likely to occur at the merge points of the corridor, so careful consideration will need to be given as to their location.

5.2.2 Cost



Lane reductions on Hindmarsh Drive at Eggleston Crescent and at Launceston Street are expected to impact crash frequency with the same reductions indicated in Option 1 a (see Table 4). For this option, the reductions would apply to the crash history at each intersection.

5.3 Option 2 – Median Closure on Hindmarsh Drive 5.3.1 Physical Description

This treatment prevents right turn movements into and out of Eggleston Crescent by closing the median on Hindmarsh Drive as shown in Figure 8. Hindmarsh Drive would be reduced to two through lanes as detailed in Option 1. The proposed treatment would reduce the number and / or severity of all key crashes; however it would seriously impact access for Chifley residents.

Figure 8 Option 2 – Median Closure on Hindmarsh Drive at the Intersection



15

5.3.2 Cost



Median closure on Hindmarsh Drive is expected to have the following impact on crash frequency:




100% Austroads 2009, Guide to Road Safety Part 8




60% Engineering Judgement*

*; Due to unavailability of some assumed reductions related to the proposed treatment, assumed crash reduction was applied based on engineering judgement.

5.4 Option 3 –Close Intersection and Signalise Hindmarsh Drive / Launceston Street / McDonald Street Intersection


This treatment closes the Hindmarsh Drive / Eggleston Crescent intersection; opens McDonald Street to Hindmarsh Drive, and signalises the resulting cross intersection of Hindmarsh Drive / Launceston Street / McDonald Street.

This treatment takes into consideration both the Hindmarsh Drive / Eggleston Crescent intersection and the Hindmarsh Drive / Launceston Street intersection. It would reduce the severity and number of key crashes occurring at both Hindmarsh Drive / Eggleston Crescent and Hindmarsh Drive / Launceston Street. The proposed treatment is shown in Figure 9.



16

Figure 9 Option 3 – Intersection closure and signalisation of Hindmarsh Drive / Launceston Street / McDonald Street

intersection

5.4.2 Cost

The estimate of probable cost to install this treatment is $500,000 excluding GST. No detailed design or assessment of the existing hardware, underground services, or intersection performance (SIDRA) has been undertaken.


Closure of the subject intersection and signalisation of a new cross intersection at Hindmarsh Dive / Launceston Street / McDonald Street is expected to have the following impact on crash frequency:









Lane change crash (crash codes 305 – 307)

45% Engineering Judgement*

*; Due to unavailability of some assumed reductions related to the proposed treatment, assumed crash reduction was applied based on engineering judgement.



17

6.0 Analysis and Recommendation At the intersection of Hindmarsh Drive / Eggleston Crescent, the following options were assessed:

- Option 1 a – Reduce Hindmarsh Drive to two through lanes at the intersection.

- Option 1 b – Reduce Hindmarsh Drive to two through lanes at Eggleston Crescent and at Launceston Street

- Option 2 – Median closure on Hindmarsh Drive

- Option 3 – Close the intersection and install new signalised cross intersection at Hindmarsh Drive / Launceston Street / McDonald Street.

6.1 Options Comparison 6.1.1 Expected Crash Reductions

Expected crash reductions were tabulated by applying reductions available from road safety literature to the 5-year crash experience in the intersection. Where crash reductions were not available through research, engineering judgement and experience were used to determine potential benefits. Only crashes of the particular type identified through literature or by engineering judgment, and on the correct approach to be affected by the option, were considered targeted crashes for reduction. The results are detailed in the “Target Crashes” and “Assumed Reduction” columns in Table 9 and Table 10, below.

Option 1 a, reducing Hindmarsh Drive to two through lanes at the intersection would reduce adjacent approach crashes (codes 101-109) by 10%, opposing turn crashes (codes 202-206) by 15%, rear-end crashes (codes 301 – 304) by 60% and lane change crashes (codes 305 – 307) by 40%.

Option 1 b, reducing Hindmarsh Drive to Two through Lanes at Eggleston Crescent and at Launceston Street, would reduce total crashes at both Hindmarsh Drive intersections with Eggleston Crescent and Launceston Street. Benefit-cost analysis was conducted based on the 5-year crash history at both intersections. The treatment would reduce total adjacent approach crashes (codes 101-109) by 10%, opposing turn crashes (codes 202-206) by 15%, rear-end crashes (codes 301 – 304) by 60% and lane change crashes (codes 305 – 307) by 40%.

Option 2, median closure and lane reduction on Hindmarsh Drive would reduce adjacent approach crashes (codes 101-109) by 100%, opposing turn crashes (codes 202-206) by 100% and rear-end crashes by 60%.

Option 3, closure of the subject intersection and creation of a new signalised intersection at Hindmarsh Drive / Launceston Street / MacDonald Street will reduce total crashes at both Hindmarsh Drive intersections with Eggleston Crescent and Launceston Street. Benefit-cost analysis was conducted based on the 5-year crash history at both intersections. The treatment would reduce total adjacent approach crashes (codes 101-109) by 70%, total opposing turn crashes (codes 202-206) by 45%, rear-end crashes (codes 301 – 304) by 40%, and lane change crashes (codes 305 – 307) by 45%.

6.1.2 Economic Analysis

The 2011 crash costs were obtained from Roads ACT to develop an economic analysis of the costs and benefits of Black Spot improvements. Crash cost by crash type was used for costing future crashes. When crash types were encountered that did not have indicative costs; the cost of an average property damage crash was substituted in the analysis. The crash costs are summarised in Table 7and Table 8.

Table 7 Crash Costs in the Australian Capital Territory

Crash Code Crash Description Cost per Crash

101-109 Intersection, adjacent approaches $ 35,265

201 Head-on $ 138,301

202-206 Opposing vehicles; turning $ 32,584

301 – 304 Rear-end $ 19,909



18

Crash Code Crash Description Cost per Crash

305 – 307 Lane change $ 21,557

001 – 003 Vehicle hits pedestrian $ 163,946

706 – 707 Loss of Control (L or R turns) $ 82,427

401 – 402 Hit parked vehicle $ 21,586

601 Hit parked vehicle $ 23.675

501 – 506 Overtaking $ 28,113

901 Fell from moving vehicle $ 70,222

Table 8 Crash Cost by Severity in the Australian Capital Territory

Severity Cost per Crash

Fatal $2,314,504.00 Serious Injury $381,099.00 Minor Injury $60,173.00 Property Damage Only $18,096.00

The present-day value of the expected costs and benefits over a 10-year project life for each option were analysed. The results are detailed in Table 9 and Table 10, below.



19Table 9 Benefit/Cost Analysis for Single-Location Options

LOCATION: Hindmarsh Drive / Eggleston Street OPTION 1 a OPTION 2

Discount rate 7% Reduce Hindmarsh Drive to Two Through Lanes at the Intersection

Median Closure with Left Turn Deceleration / Acceleration Lanes

Years of Crash Data 5 Initial Cost of Treatment $94,000 Initial Cost of Treatment $122,000

Assumed Project Life 10 Annual Maintenance $4,700 Annual Maintenance $6,100

Crash Code Crash Description Tota

l C

rash

es

Cos

t per

C

rash

Cos

t of

Cra

shes

Targ

et

Cra

shes

Ass

umed

R

educ

tion

Dis

coun

ted

Ben

efits

Targ

et

Cra

shes

Ass

umed

R

educ

tion

Dis

coun

ted

Ben

efits

101-109 Intersection, adjacent approaches 6 $ 35,265 $211,590 6 10% $29,772 2 100% $99,075

201 Head-on $ 138,301 0 $0

202-206 Opposing vehicles; turning 4 $ 32,584 $130,336 4 15% 27,463 4 100% $183,085

301 - 304 Rear-end 20 $ 19,909 $398,180 16 60% 268,468 18 60% 302,038

305 - 307 Lane change 1 $ 21,557 $21,557 1 40% 12,113

001 - 003 Vehicle hits pedestrian $ 163,946 0

706 - 707 Loss of Control (L or R turns) $ 82,427 0

401 - 402 Hit parked vehicle $ 21,586 0

601 Hit parked vehicle $ 23.675 0

501 - 506 Overtaking $ 28,113 0

901 Fell from moving vehicle $ 70,222 0

Other 1 $18,086 $18,086

TOTAL 32 $779,749 27 $337,776 24 $584,198

B/C Ratio NPV Discounted Costs

B/C Ratio

NPV Discounted Costs

2.66 $210,765 $127,011 3.54 $419,354 $164,844



20Table 10 Benefit/Cost Analysis for Two-Location Options

LOCATION: Hindmarsh Drive / Eggleston Street OPTION 1 b OPTION 3

Discount rate 7% Reduce Hindmarsh Drive to Two Through Lanes Eggleston Cr. & Launceston St.

Intersection Closure and new signalisation at Hindmarsh Dr. / Launceston St. / MacDonald St

Years of Crash Data 5 Initial Cost of Treatment $230,000 Initial Cost of Treatment $500,000

Assumed Project Life 10 Annual Maintenance $11,500 Annual Maintenance $25,000

Crash Code Crash Description Tota

l C

rash

es

Cos

t per

C

rash

Cos

t of

Cra

shes

Targ

et

Cra

shes

Ass

umed

R

educ

tion

Dis

coun

ted

Ben

efits

Targ

et

Cra

shes

Ass

umed

R

educ

tion

Dis

coun

ted

Ben

efits

101-109 Intersection, adjacent approaches 16 $ 35,265 $525,520 16 10% $73,821 6 70% $208,057

201 Head-on 0 $ 138,301 0 $ $0

202-206 Opposing vehicles; turning 6 $ 32,584 200,982 6 15% $42,348 4 45% $82,388

301 - 304 Rear-end 30 $ 19,909 585,480 30 60% 493,460

305 - 307 Lane change 2 $ 21,557 38,418 2 40% 21,587

001 - 003 Vehicle hits pedestrian $ 163,946 0 $0

706 - 707 Loss of Control (L or R turns) $ 82,427 0 $0

401 - 402 Hit parked vehicle $ 21,586 0 $0

601 Hit parked vehicle $ 23.675 0 $0

501 - 506 Overtaking $ 28,113 0 $0

901 Fell from moving vehicle $ 70,222 0 $0

Other 5 $18,086 88,950 $0

TOTAL 59 $1,439,350 54 $648,076 10 $290,445

B/C

Ratio NPV Discounted

Costs B/C Ratio

NPV Discounted Costs

2.09 $320,444 $310,771 0.58 -$209,491 $499,936



21

The results of the cost benefit analysis are summarised in Table 11.

Table 11 Summary of Benefit to Cost Analysis

OPTION Treatment Cost B/C Ratio NPV

OPTION 1 a Lane reduction of Hindmarsh Drive at the Eggleston Crescent $94,000 2.66 $210,765

OPTION 1 b Lane reduction of Hindmarsh Drive at the Eggleston Crescent and Launceston Street $230,000 2.03 $320,444

OPTION 2 Median closure with let turn deceleration / acceleration lanes $122,000 3.54 $419,354

OPTION 3

Closure of the subject intersection with installing new signalised intersection at Hindmarsh Dr. / Launceston St. / MacDonald St $370,000 0.58 -$209,491

The benefit to cost analysis indicates that the option with greatest Benefit Cost Ratio is Option 2, closure of the median in Hindmarsh Drive. This option reduces many of the crashes in the intersection, and would reduce severity most effectively. The option would significantly reduce access for the suburb of Chifley.

Option 1 a, through lane reduction yields crash reductions valued at over two times its cost for the Eggleston Crescent intersection, Option 1 b, offers a similar return on investment is for the nearby Launceston Street intersection. These options are relatively low cost, and they reduce right angle crashes and have the strongest effect on rear-end crashes.

Option 3, closure of Eggleston Crescent and signalisation at Launceston Street is effective against the most severe right angle crashes at both intersections, however it is more costly to implement. This option does preserve access for both neighbouring suburbs.

6.2 Improvements to Correct Existing Deficiencies In the event that no improvement option is determined through the economic analysis required by the black spots program, the potential crash risk of existing deficiencies can be evaluated using road safety audit principles. The probable frequency of crash occurrence resulting from each deficiency is rated from improbable to highly probable. The severity of crashes resulting from the deficiency is rated as minor, moderate or major. Level of risk is assigned by a matrix. Improbable crash frequencies which result in minor or moderate severity are considered low level of importance. The level of risk matrix is detailed in Table 12.

Table 12 Level of Risk

Crash Frequency

Highly Probable Occasional Improbable

Seve

rity Major High High Medium

Moderate High Medium Low

Minor Medium Low Low

Risks should be corrected or minimised when cost of treatment corresponds or is less than the risk level presented by the deficiency: low level risks should be corrected if the treatment cost is low; medium level risks should be corrected if the treatment cost is medium or lower; and high level risks should be corrected if the treatment cost is high, medium or low.



22

6.2.1 Relocate Give – Way Warning Sign on Northbound Eggleston Crescent

On northbound Eggleston Crescent, the Give-Way warning sign is hidden by large tree. It is not likely that the hidden warning sign causing frequent crashes, however the lack of a warning may result in minor crashes involving property damage. This issue presents a low level of risk. Low risk deficiencies should be corrected in cases where the treatment cost of correcting the deficiency is also low. The order of cost to relocate the warning give-way sign is $500 excluding GST.

6.2.2 Existing Deficiencies Summary

The existing deficiencies and treatments are summarised in Table 13.

Table 13 Existing Deficiency Summary

DEFICIENCY RISK TREATMENT COST ESTIMATE

Hidden Give-Way Warning Sign Low Relocate Sign $500

6.3 Recommendation At the intersection of Hindmarsh Drive and Eggleston Crescent, four treatments were proposed and analysed for crash reduction abilities and cost-effectiveness: Option 1 a, lane reduction and auxiliary lanes at Eggleston Crescent; Option 1 b, lane reduction and auxiliary lanes at Eggleston Crescent and Launceston Street; Option 2, lane reduction and median closure at Eggleston Crescent; and Option 3, closure of the intersection at Eggleston Crescent, and signalisation of a new intersection at Hindmarsh Drive / Launceston Street / McDonald Street.

Options 1a and 1 b are recommended as viable candidates for implementation. Option 1 b is recommended because it offers similar crash reductions to two intersections, and it maintains consistency and driver expectations.

It is worth noting that the Austroads Guide to Traffic Management (Part 3) states that the maximum carrying capacity of a lane to maintain a Level of Service (LOS)‘C’ is 1280 veh/hr/lane. The current peak hour volume on this section of Hindmarsh Drive is approximately 2,300 per hour in the peak direction (across three lanes). With the proposed reduction in traffic lanes from three to two between Eggleston Crescent and Launceston Street, this would equate to around 1,200 veh/hr/lane – within the LOS C criteria. However, slight delays are likely to occur at the merge points of the corridor, so careful consideration will need to be given as to their location.

Option 2, median closure, is an effective measure, however closing the median would result in a major loss of access for Chifley residents. Option 3 reduces total crashes occurring at the Eggleston Crescent and Launceston Street intersections with Hindmarsh Drive. It is, however, more costly to implement and crash reduction benefits do not outweigh costs sufficiently to make it a strong contender among black spot projects.

The existing deficiencies in the intersection should be corrected based on the potential risk identified using road safety audit principles. The Give –Way warning sign on Eggleston crescent should be relocated to improve legibility at the intersection and reinforce priority.



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Appendix A

Crash Data for the ACT (2007 - 2010)



A-1

Appendix A Crash Data for the ACT (2007 - 2010)

CRASH DATA for the ACT (2007 - 2010)

Total Crashes by Severity + Traffic Control Type (2007-2010)

Traffic Control PD Injury Fatal Sub Totals % of total crashes % of Injury / Fatal 0 Unknown 205 7 0 212 2.73% 3.30% 1 Uncontrolled 14513 1171 38 15722 202.58% 7.69% 2 Control Not Operated 49 3 0 52 0.67% 5.77% 3 Traffic Lights 6746 319 5 7070 91.10% 4.58% 4 Give Way Sign / Roundabout 6059 400 11 6470 83.37% 6.35% 5 Stop Sign 845 66 0 911 11.74% 7.24% 6 Police 28 4 0 32 0.41% 12.50% 7 School Crossing 20 3 0 23 0.30% 13.04% 8 Marked Pedestrian Crossing 275 35 1 311 4.01% 11.58% 9 Other 191 10 0 201 2.59% 4.98%

TOTAL 28931 2018 55 31004 399.48% 6.69%

Source: multiple publications - see below

Total Crashes by Severity and Traffic Control Type (2010) Traffic Control PD Injury Fatal Sub Totals % of total crashes % of Injury / Fatal

0 Unknown 1 0 0 1 0.01% 0.00% 1 Uncontrolled 3599 374 10 3983 51.32% 9.64% 2 Control Not Operated 7 1 0 8 0.10% 12.50% 3 Traffic Lights 1535 105 2 1642 21.16% 6.52% 4 Give Way Sign / Roundabout 1650 125 4 1779 22.92% 7.25% 5 Stop Sign 182 16 0 198 2.55% 8.08% 6 Police 5 1 0 6 0.08% 16.67% 7 School Crossing 3 1 0 4 0.05% 25.00% 8 Marked Pedestrian Crossing 71 14 0 85 1.10% 16.47% 9 Other 49 6 0 55 0.71% 10.91%

TOTAL 7102 643 16 7761 100.00% 8.49%

Source: '2010 Road Traffic Crashes in the ACT', Traffic Management and Safety, April 2011



A-2



TOTAL 7312 516 11 7839 101.01% 6.72%

Source: '2009 Road Traffic Crashes in the ACT', Traffic Management and Safety, April 2010



TOTAL 6857 358 14 7229 93.15% 5.15%

Source: '2008 Road Traffic Crashes in the ACT', Traffic Management and Safety, May 2009



TOTAL 7660 501 14 8175 105.33% 6.30%

Black Spot Feasibility Study Hindmarsh Drive / Eggleston Crescent Intersection

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