Evidence in support of my Submission Regarding the Pūhoi · If there is an engineering reason for...
Transcript of Evidence in support of my Submission Regarding the Pūhoi · If there is an engineering reason for...
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Evidence in support of my Submission Regarding the Pūhoi
to Wellsford Road of National Significance Notice of
Requirement
Contents
Contents .................................................................................................................................................. 1
1 Operational Noise —Proposed Consent Condition ........................................................................ 2
2 Operational Noise—the relationship between the AEE and mitigation; and why it is important
that the AEE identify all adverse noise effects ....................................................................................... 2
2.1. Incomplete Assessment of Adverse Environmental Effects ................................................... 2
2.2. The RMA and BPO ................................................................................................................... 4
2.3. Aggregating Properties ........................................................................................................... 4
2.4. Mitigation Options Where Noise is Considered Reasonable (ie BPO does not apply) ........... 5
2.5. Reasonable Noise .................................................................................................................... 6
3 Kaipara Flats Road / SH1 Intersection ............................................................................................. 7
3.1. AEE and EIC Statements re this Intersection .......................................................................... 7
3.2. Description of Model .............................................................................................................. 9
3.3. Additional Information .......................................................................................................... 10
3.4. Base Model ........................................................................................................................... 10
3.5. Sensitivity Analyses ............................................................................................................... 12
3.6. Appendix 1 - Additional Data from NZTA - Kaipara Flats / Sh1 Intersection Traffic flows .... 14
3.7. Appendix 2 - Additional Data from NZTA - Roundabout Traffic flows .................................. 14
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1 Operational Noise —Proposed Consent Condition
The Proposed Consent condition number 72 requires "The Requiring Authority shall implement
low-noise road surfaces no later than twelve (12) months following completion of construction of
the Project."
If there is an engineering reason for the potential twelve month delay it should be documented and
hence able to be tested by the Board of Inquiry Process. Otherwise, the proposed condition should
be modified to require the agreed low noise road surface be in place prior to the project opening for
traffic.
2 Operational Noise—the relationship between the AEE and
mitigation; and why it is important that the AEE identify all adverse
noise effects
The following expands upon matters discussed in my Submission and specifically documents a link
between assessment and mitigation that is only hinted at in my Submission.
2.1. Incomplete Assessment of Adverse Environmental Effects
The AEE only covers some situations where there are adverse noise effects—namely PPFs (generally
residences) within 200 meters that are built on (i.e. "occupied"). There are other situations that are
not covered—
properties within 200m that are not built on
properties beyond 200m whether built on or not
those parts of properties within 200m that are not built on
This is problematic for the following reasons—
1. Many residents are unable to determine the likely noise impact of the proposed motorway
2. The RMA requires a full assessment of effects. The RMA has two potentially conflicting
paragraphs—
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Schedule 4 S1(d) "Matters that should be included in an assessment of effects on the
environment" requires "an assessment of the actual or potential effect on the
environment of the proposed activity", whereas
Schedule 4 S2 "Matters that should be considered when preparing an assessment of
effects on the environment" requires "any discharge of contaminants into the
environment, including any unreasonable emission of noise and options for the
treatment and disposal of contaminants:"
In my view there is a clear requirement in Schedule 4 S1(d) to include all adverse effects
(including noise and without limiting it to only unreasonable noise) and that requirement is
not extinguished by S2 which refers to consideration rather than inclusion.
3. The AEE provides no input on what is considered unreasonable or why. It relies upon the
Standard (NZS 6806:2010) which I discuss in my Submission should not be the controlling
document. See also the discussion below on Reasonable Noise.
4. There is an argument that undeveloped properties cannot have specific site focused
mitigation as there is no residence to focus upon. This is not true in modern subdivisions
where sites are generally identified at the time of subdivision. Such situations should be
specifically allowed for in NZTA's mitigation analysis.
5. No consideration is given to outdoor living considerations which in rural areas frequently
apply well beyond the location of the residence.
6. Government policy per the Cabinet paper "2013 Resource Management Reforms: Public
Works Act 1981: Amendments" 1 regarding proposed changes to the Public Works Act
approves work to proceed on a bill that would include a Solatium payment for undeveloped
properties that are acquired. This recognises that undeveloped land has a value to its owner
beyond its market value. Although this will apply only to land that is taken its reasonable to
assume that other nearby land (which could have been taken had a different alignment been
chosen) should similarly qualify under this proposal. Further, although this is not currently
1 http://www.linz.govt.nz/sites/default/files/docs/crownproperty/cab-min-2013.pdf
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legislated for some weight should be placed upon it as it is approved by Cabinet for inclusion
in the legislative process.
Therefore undeveloped land should be considered.
7. The aggregate impact of considering currently excluded properties means that an overall
better solution to noise should be possible. This is discussed further below.
2.2. The RMA and BPO
The RMA (s16) places a duty on occupiers to use " the best practicable option to ensure that the
emission of noise from that land or water does not exceed a reasonable level". This addresses noise
emissions that exceed the threshold of "reasonable" but is silent about adverse noise effects that
are below that threshold. There remains a requirement to make an attempt to mitigate those effects
but without being constrained by undertaking the Best Practicable Option.
2.3. Aggregating Properties
The impact of mitigating (partially or fully) distant properties or unoccupied nearby properties may
well provide some benefits to other nearby properties. And by implication, aggregating the
mitigation work into one "package" would in some situations allow for a greater level of mitigation
for all concerned. (There is an Appendix to the Standard that takes a similar approach but only
considers properties with > 57dB. Extending it to all properties with adverse effects should
significantly reduce the adverse noise effects across a wide area of land.)
Therefore a better overall result should be obtained if properties below the reasonable threshold
are included in the analysis of mitigation.
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2.4. Mitigation Options Where Noise is Considered Reasonable (ie BPO does not
apply)
Road Surface Mitigation
There is a possible argument that using a low noise road surface and no other form of mitigation
meets the mitigation requirements for these residences. If this is the case (which I do not agree
with) there should be an analysis within the AEE of the impact of including low noise surface in areas
where it is not currently proposed. (This analysis should be provided anyway.)
If a low noise road surface is proposed to mitigate properties with unreasonable noise levels, then
this alone should not completely satisfy the obligation to consider mitigation of other properties
with lesser noise levels. Rather the low noise road surface should be considered as a part of such
mitigation.
Therefore road surface mitigation alone does not meet the requirements of the RMA unless it is
demonstrated that other measures to reduce noise levels necessitate following BPO. i.e. Some
additional analysis is required before dismissing barriers, bunds etc.
Other (Focused) Forms of Mitigation
Forms of mitigation such as barriers and bunds should be considered for all properties once the
impact of low noise road surfacing (where proposed) is allowed for. Because there is not a need to
meet BPO in situations where the noise levels are deemed Reasonable, the arguments in the AEE
and Operational Noise Assessment Report about heights, visual impacts and costs of walls and bunds
should be largely discounted.
A clear example where additional barriers may be of benefit is the Carran Road viaduct. In this case
its likely because of the shape of the valley that significant amounts of noise will propagate both east
and west (the latter into particularly quiet areas). An analysis of raising the barrier height of that
viaduct beyond what is required for safety reasons should show significant benefit to quite a number
of properties.
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2.5. Reasonable Noise
The approach being taken by NZTA follows the Standard (which I separately argue in my Submission
should not be the ruling document) in drawing a line at 57dB. Those under this noise level receive no
mitigation and those over are considered under the BPO sections of the RMA.
As well as there being no clear justification for using 57B, this creates a nonsense in the hypothetical
case where—
Property 1 Before project 56 db
With project 57 db (i.e. no noticeable sound difference as < 3dB)
Mitigation considered because overall level considered not Reasonable
Property 2 Before project 46 db
With project 56 db (i.e. doubling of sound level)
Mitigation not considered because overall level considered Reasonable
Surely a doubling of sound levels deserves consideration for mitigation whereas an indiscernible
increase of 1 dB does not. This is out of line with the RMA requirement (s2(a)) to consider the
sensitivity of the receiving environment, and is it wrong from a common sense perspective.
Whilst I do not expect this exact situation to occur in this project there will be situations where those
with smaller increases in noise are treated better than those with larger increases in noise. This
scenario shows that the Standard has not been well considered—despite being produced by experts.
This is presumably because it has not been adequately considered against real world situations.
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3 Kaipara Flats Road / SH1 Intersection
In order to gain an understanding of the existing Kaipara Flats intersection and how it would perform
with the motorway in operation, I wrote a program to model traffic flows. (I programmed this as I do
not have access to appropriate simulation software). I recognise that my model has some
approximations but nevertheless I believe that (subject to using the correct parameters) it provides a
reasonable view of the intersection.
Summaries of various scenarios are shown below. The clear result using the 2026 traffic predictions
from NZTA is that the Kaipara Flats Road / SH1 intersection is at best marginal and depending on
assumptions made will at times be unable to cope with peak hour traffic flows.
One scenario of particular concern is the 9% growth forecast which equates to 2 years at 4.4%
compound annual growth. This shows a very substantial deterioration in performance of the
intersection and indicates that using the 2026 traffic predictions may be quite inappropriate should
the opening of the motorway be delayed.
3.1. AEE and EIC Statements re this Intersection
It appears that NZTA's thinking re this intersection has advanced. Whereas the AEE solely addresses
traffic turning from SH1 southbound into Kaipara Flats Road2 the EIC also makes allowance for a
southbound acceleration lane3. The latter issue is the most critical aspect of this intersection. The
generalised nature of the wording in the EIC makes it unclear quite what NZTA proposes (although I
do understand that NZTA needs some design flexibility). Does it mean that—
1. SH1 southbound traffic will have a safe (and fully separated) holding lane in the centre of
SH1 to use whilst waiting for a gap in north bound traffic before turning into Kaipara Flats
Road, and
2. Kaipara Flats Road traffic turning south into SH1 will have a safe (and fully separated)
holding lane in the centre of SH1 to accelerate to 100kph (or whatever the expected target
2Operational Traffic Assessment Report p 56—"The Project design has allowed for the upgrade of the Kaipara Flats Road
intersection immediately north of the proposed Project tie-in with SH1 with the provision of a right turn bay." 3Statement of evidence of Andrew Bell (transportation and traffic) for the New Zealand Transport Agency para 55 "In my
assessment I recommended changes to the Kaipara Flats Intersection including a right turn bay on SH1 in the southbound direction and a southbound acceleration lane."
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speed will be at the point of merging) before needing to merge with other SH1 southbound
traffic?
If these are what is meant within the EIC titled "Statement of evidence of Andrew Bell
(transportation and traffic) for the New Zealand Transport Agency" and in proposed designation
condition 74 then much of my concern about this intersection is addressed. But this leaves unclear
several matters—
the appropriate year to use for traffic modelling given the unknown completion date of the
project,
the intersection capacity especially with regard ex Kaipara Flats Road traffic (as the proposed
condition only addresses safety),
an understanding of what a "Stage 3 Safety Audit" comprises, and
whether there will be any public scrutiny of the proposal (as there is of the overall project).
Based on present information, I believe that the proposed consent condition number 74 should be
amended to —
require the proposed upgrade to be based on the predicted traffic model ten years after
opening of the motorway to traffic,
require the proposed upgrade have sufficient capacity to allow traffic from Kaipara Flats
Road to continue to flow safely with minimal delays (as written it currently only requires
safety), and
require a reasonable level of public scrutiny to the final solution
And that NZTA provide a definition of what a Stage 3 Safety Audit comprises.
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3.2. Description of Model
The basics of the program are—
1. All modelling is done in seconds and simulations in tenths of a second. This includes
determining delays between traffic passing key points such as Top-Of-The-Dome to Kaipara
Flats Road and Kaipara Flats Road to Roundabout
2. Inbound traffic patterns are generated randomly, but adjusted to allow for safe following
distances.
3. South bound traffic is bunched behind slow traffic from the Top-Of-The-Dome. Bunching is
controlled by parameters.
4. North bound traffic at Kaipara Flats Road all comes from the proposed roundabout
5. The proposed roundabout has 2 lane entrances, 2 lane exits and 2 lanes going around. This
is per the published drawing R-115
6. Traffic from the new motorway is assumed to arrive randomly at the roundabout (subject to
an adjustment for safe following distances)
7. Traffic from Warkworth is assumed to arrive at the roundabout in bursts reflecting the lights
cycle at Hill St. The cycle length is 100 seconds and sufficient time is allowed to enable north
bound traffic to not significantly back up
8. The impact of the new Hudson Rd lights is assumed to have no additional effect on traffic
bunching so is ignored. (This is an approximation)
9. The roundabout follows standard conventions re Give Way signs.
10. All southbound traffic from Kaipara Flats Road goes on to the roundabout
11. Various parameters allow changes to traffic spacing assumptions including—
Safe gap between vehicles
Safe gap before turning from Kaipara Flats Road to SH1 southbound
Safe Gap before entering the Roundabout
12. Various parameters allow traffic levels to be set at the following points—
Southbound - split between destination Warkworth and Motorway
Northbound from Motorway - split between destinations SH1 north and Warkworth
Northbound from Warkworth - split between destinations Motorway (southbound) and
SH1 northbound
13. Ability to adjust overall traffic volumes by a percentage (to roughly simulate earlier or later
years)
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14. The model was run 100 times under each scenario in order to get a feel of the impact of
randomness.
15. The key outputs are—
the number of gaps available to traffic turning from Kaipara Flats Road and
the number of vehicles that those gaps could accommodate (allowing for a percentage of
gaps sufficient for multiple vehicles)
16. The model does not model average wait times for traffic waiting on Kaipara Flats Road to
turn south onto SH1. Rather, it counts the number of gaps sufficiently large to undertake
such a manoeuvre, and the number of vehicles that each gap should safely allow to turn.
17. The software is written using Excel/VBA (Visual Basic for Applications—the Microsoft Office
macro language). It uses spreadsheets to manage parameters and provide detailed outputs.
All logic is written in VBA.
3.3. Additional Information
Some of the information required is provided in the AEE and Operational Traffic Assessment Report
but these lack details about the origin and destination required to complete the model. To obtain
the rest, I approached NZTA and received the additional information required. This predominantly is
a breakdown of destinations of traffic entering the roundabout and entering Kaipara Flats Road.
Some other actual and apparent discrepancies in the Operational Traffic Assessment Report traffic
volumes were also resolved. The additional information is repeated in Appendices 1 and 2.
3.4. Base Model
The following outlines the key assumptions in the Base Model.
Southbound bunching
Target speed
5% 80kph
10% 90kph
Remainder 100kph
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Vehicle Gaps
Safe gap between vehicles 1.5 sec *
Safe gap before turning from Kaipara Flats Road
to SH1 southbound
7 sec
Safe Gap before entering the Roundabout 5 sec
* The Road Code says 2 sec but I suspect that this is not widely followed.
Warkworth Lights
Cycle 100 sec
North bound component 60 sec
(Set to be sufficient for all north bound traffic to
avoid significant queuing)
Traffic volumes at Roundabout
Aggregate
To
WW
To
MW
To
North
From North (SH1) 756 524 232 0
From Warkworth 1231 0 502 729
From Motorway 525 258 0 267
Total 2512 782 734 996
Notes:
1. These volumes are obtained from the NZTA Additional Data - Appendix 2
2. The traffic volumes at Kaipara Flats Road are assumed to be the same as those north-
bound from the roundabout. But note that NZTA's Saturn model assumes an additional
approx 100 vehicles will join SH1 north-bound between Hudson Rd and Kaipara Flats
Road.
Base Model Result
Gaps available for Kaipara Flats Road Traffic to turn onto SH1 southbound
Base Model Average Gaps Standard Dev Gaps Average Vehicles
19 3.8 33
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This compares with the additional data provided by NZTA (Appendix 1) which shows an average of
34 vehicles make this turn in the busy hour. i.e. The intersection can handle the incoming 34
vehicles just under half of the time (actually 40%).
Note: The impact of applying a degree of randomness to the ex Kaipara Flats Road traffic will likely
worsen the performance of this intersection.
3.5. Sensitivity Analyses
Safe gap between vehicles (on motorway / open road)
Base Model + Safe gap
between vehicles
Average Gaps Standard Dev
Gaps
Average Vehicles
1.5 sec (Base model) 19 3.8 33
2.0 sec 15 3.7 27
4.0 sec 1 0.6 2
The 2 sec scenario is in line with the Road Code recommendation for dry weather and 4 sec for wet
weather. Clearly there is a serious problem in wet weather!
Safe gap for turning from Kaipara Flats Road to SH1 southbound
Base Model + Safe gap
before turning from
Kaipara Flats Road to
SH1 southbound
Average Gaps Standard Dev
Gaps
Average Vehicles
5 sec 41 5.2 86
6 sec 28 5.1 52
6.5 sec 23 3.9 39
7 sec (Base model) 19 3.8 33
7.5 sec 16 4.0 26
8 sec 12 3.1 20
9 sec 9 3.1 14
10 sec 7 2.6 9
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This shows for each modelled gap, that there are quite large number of gaps that are of slightly
shorter duration than that gap. This raises the possibility that if traffic is waiting to turn some people
will take risks and attempt to turn when the gap is a little small with a consequential risk of
accidents.
Increased Traffic
Add 9% to the traffic levels in all directions—equivalent to 2 years growth of 4.4% compounded.
Average Gaps Standard Dev
Gaps
Average Vehicles
Base model 19 3.8 33
9% Traffic increase 14 3.3 24
This is showing that even a small increment in the traffic above projected 2026 levels results in the
Kaipara Flats Road / SH1 intersection backing up on Kaipara Flats Road. This finding has significant
ramifications should the opening of the motorway be delayed and the "base-line" traffic levels are
therefore higher than modelled.
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3.6. Appendix 1 - Additional Data from NZTA - Kaipara Flats / Sh1 Intersection
Traffic flows
The following was supplied by NZTA. From further emails, I understand that each rectangular box is
interpreted as—light vehicles on top, heavy vehicles on bottom.
3.7. Appendix 2 - Additional Data from NZTA - Roundabout Traffic flows
The following was supplied by NZTA.