Works and Infrastructure
Committee
26 November 2015
REPORT R5063
Intersection Safety Improvements - Main Road
Stoke/Elms Street
1.
Purpose of Report
1.1
To approve the inclusion of the safety improvement works at the
intersection of Main Road Stoke and Elms Street in the 2015/16 Minor
Improvements Programme.
1.2
To approve consultation to occur on amending the Speed Limits Bylaw to
allow the reduction of speed on Main Road Stoke between Saxton Road
and Salisbury Road to 60km/h.
2.
Delegations
2.1
The Works and Infrastructure Committee has delegated authority to
perform all functions, powers and duties relating to the operation of
roads conferred on Council by relevant legislation. In this case the
controlling legislation is the Land Transport Act (LTA).
3.
Recommendation
THAT
the
report
Intersection
Safety
Improvements - Main Road Stoke/Elms Street
and its attachments (A1463084 and A1452019)
be received;
AND THAT the design and construction of road
safety improvements at the intersection of Main
Road Stoke and Elms Street be included as a
priority in the minor improvements work
programme for the 2015/16 financial year;
AND THAT consultation to seek the community’s
views on a reduction of speed on Main Road
Stoke between Saxton Road and Salisbury Road
to 60km/h is undertaken;
AND THAT the chairman of the Works and
Infrastructure
Committee
and
Councillors
.......... and ........... be delegated authority to
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hear oral feedback at a hearing on 28 February
2016.
4.
Background
4.1
In response to a number of highly publicised crashes at the intersection
of Main Road Stoke and Elms Street, a crash reduction study was
undertaken by Council officers and local representatives from the New
Zealand Police in August 2015. A network location plan is shown in
attachment 1.
4.2
The crash reduction study identified the need to urgently improve the
layout of the intersection to more closely match the available visibility to
the operating speed for vehicles turning out of Elms Street. Almost all
drivers were observed to be struggling with making the right turn out of
Elms Street due to a combination of high speed, high traffic volumes and
vehicles turning left into Elms Street blocking the sightline to the
northbound straight through traffic on Main Road Stoke.
4.3
As a result officers installed a temporary speed limit reduction to 50km/h
using the temporary traffic management rules in the Land Transport Act.
This was an interim solution until a more permanent solution is
developed.
4.4
The 2015 Government Policy Statement focuses on a reduction in
crashes that result in death or serious injury. This focus flows through to
the Safer Journeys strategy that has been developed by the Ministry of
Transport and the NZ Transport Agency.
4.5
The most important factor that determines injury severity is the impact
speed of the vehicles involved in a crash. In the case of the intersection
of Main Road Stoke and Elms Street the predominant crash type involves
side impact. Research shows that for this crash type a 50km/h impact
speed results in a 90% chance of survival of the vehicle occupants. At
80km/h the chance of survival reduces to approximately 50%. The Safer
Journeys strategy acknowledges that drivers do make mistakes, even at
the safest intersections, and seeks to minimise the chances of them
dying as a result of their mistake.
4.6
NZ Transport Agency has advised that the new Speed Management
Guidelines are expected to be released at the end of 2016. Until then NZ
Transport Agency has requested that road controlling authorities only
undertake speed limit changes where it is essential that a specific road
safety issue is mitigated.
5.
Discussion
Speed vs cost trade-off
5.1
Design work has been undertaken to understand the options available to
council to reduce the risks to drivers at the intersection as recommended
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by the crash reduction study. During this work it became apparent that
there was the need to very clearly choose between a high cost
intersection improvement that retained the existing 80km/h speed limit
or a much lower cost option that required the speed on Main Road Stoke
to be reduced to 60km/h.
Speed limit rule
5.2
A key part of the Land Transport Rule: Setting of Speed Limits 2003 is
the matching of the speed limit to the road environment. In the case of
this section of Main Road Stoke the rule anticipates a speed limit of
around 80km/h due to the straight alignment and very few accesses or
side roads. The rule then allows for special consideration of safety issues
that may be present and gives road controlling authorities the flexibility
to match the speed limit to mitigate road safety risks.
5.3
A permanent speed limit of 50km/h to match the speed limits either side
of this section of Main Road Stoke was initially considered but found to
be too low with little chance of long term driver compliance. A 60km/h
speed limit is the lowest speed suitable for the road in the absence of
any further side roads or accesses. This speed is expected to allow
drivers on Main Road Stoke to reduce their speed to 50km/h if a vehicle
turning from Elms Street fails to give way which has a 90% chance of
survival for vehicle occupants.
6.
Options
6.1
The option to do nothing is not considered to be prudent given council’s
awareness of the issues at the intersection and the high risk of death or
serious injury as it operates currently.
6.2
60km/h option: Undertake minor works generally within the existing
carriageway to improve the sight distance to match a 60km/h speed
limit. The speed chosen represents the highest speed able to be safely
accommodated with a design that remains generally within the existing
carriageway. The total cost of this option is estimated to be
approximately $150,000 and allows for a full remark of the intersection
and some minor kerb and channel realignment works on the south west
corner of the intersection. The Benefit Cost Ratio (BCR) for this option is
estimated to be around 5 which indicates the safety improvements
represents good value for money. The preliminary design of this layout is
shown in attachment 2. This option requires purchase of a small area of
land that has low capital value. The purchase will be within the
delegated authority of the General Manager of Infrastructure.
6.3
80km/h option: Modify the intersection layout in order retain the 80km/h
speed limit. This option would be expected to cost in the order of
$650,000 - $1,200,000 depending on the level of safety treatment
chosen. Economic analysis of this option shows that the BCR would be
around 1-2.7.
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6.4
The lower cost 60km/h option has a higher BCR and it is recommended
that this option be progressed.
6.5
It is important to note that this solution is not expected to prevent all
crashes at the intersection but instead to give drivers appropriate sight
distance, in accordance with the Austroads design guides, to allow
improved decision making when turning from Elms Street. At the lower
speed, if drivers still make poor choices that result in a crash, the
severity of injuries are expected to be significantly lower.
7.
Finance
7.1
The recommended option is estimated to cost approximately $150,000
which can be accommodated within the existing minor improvements
budget of $650,000 per year. This will result in the Homezone project
and the Poleford and Gibbs Bridges strengthening works in the minor
improvements priority database being delayed by one financial year.
Improvements at the Elms Street intersection are considered by officers
to be of higher priority than the other items that will be delayed.
8.
Alignment with relevant Council policy
8.1
Improving road safety through a reduction in high severity crashes in the
transport network is a key level of service measure in the Transport
Asset Management Plan, Regional Land Transport Plan and the Long
Term Plan.
8.2
The recommendations in the report are not inconsistent with previous
council decisions.
8.3
Goal 9 of Nelson 2060 focuses on meeting people’s essential needs which
includes making them feel and be safe. The recommended road safety
improvement option is expected to improve the safety of users of the
intersection and reduce the risk of death and serious injury.
9.
Assessment of Significance against the Council’s
Significance and Engagement Policy
9.1
This decision is not significant under the Council’s Significance and
Engagement Policy.
10.
Consultation
Proposed Consultation for Speed Limit Change
10.1
The recent amendments to the Land Transport Act allow the level of
consultation to be tailored to the significance of change in accordance
with the LGA. Previously the LTA required a Special Consultative
Procedure (SCP).
10.2
Given that the decisions in this report have been assessed as not
significant under the significance policy it is recommended that an SCP
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not be undertaken although some of the consultation material and
methods will follow a very similar form as it is considered to be a clear,
concise and open way of notifying ratepayers and stakeholders of the
proposed changes.
10.3
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The following engagement with the community is recommended:

Advertise in the Nelson Mail and Council website

Letter to adjacent residents, landowners, businesses and
stakeholders

Written feedback period of seven weeks in December and January

Hearings for verbal feedback on Thursday 28 January 2016. It is
recommended that the chair of the Works and Infrastructure
Committee and two other members be delegated authority to hear
verbal feedback.

Deliberations at the 25 February 2016 Works and Infrastructure
Committee meeting
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Proposed Consultation on Intersection Layout
10.4
A letter accepting that the change in speed limit is necessary has been
received from the Automobile Association. The support is conditional on
the speed limit on Main Road Stoke between Saxton Road and Standish
Place being increased from 50km/h to 60km/h. As detailed earlier in this
report, NZ Transport Agency has requested that changes to speed limits
be restricted to those required to mitigate specific safety issues until the
new Speed Management Guidelines are released around the end of 2016.
Therefore it is proposed that a speed limit change for the section of Main
Road Stoke to the north of Saxton Road be considered once this new
guideline is released.
10.5
It is proposed to consult on the revised intersection layout with the two
corner property owners adjacent to the intersection and inform all
businesses and landowners in the Whakatu Estate industrial area of the
proposal by way of a letter drop.
10.6
Some preliminary consultation has been undertaken with the property
owner that it will be necessary to purchase land from. This land owner
has indicated willingness to sell the land if the final design requires it.
10.7
No wider consultation on this matter has as yet been undertaken by
officers.
11.
Inclusion of Māori in the decision making process
11.1
No specific consultation is proposed.
12.
Conclusion
12.1
The crash reduction study undertaken at the intersection of Main Road
Stoke and Elms Street has identified a high crash risk and recommended
that the sight lines at the intersection and the operating speed of
vehicles on Main Road Stoke be appropriately matched to improve the
safety of the intersection.
12.2
Subsequent design work has shown that the most cost effective way to
achieve the safety improvements needed is to modify the layout of the
intersection generally within the existing carriageway as well as reducing
the speed limit to 60km/h.
12.3
An SCP is not required to change the bylaw for the change in speed limit
from 80km/h to 60km/h however officers recommend community
consultation with a feedback period and hearings.
Chris Pawson
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Asset Engineer - Transport
Attachments
Attachment 1:
Location Plan (A1463084)
Attachment 2:
Proposed Intersection Layout (A1452019)
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