State Highway Speed Limit Reversal Submission Guide
Have your say at NZTA’s consultation.
Submission to New Zealand Transport Agency on:
Speed reversals and consultation - transitional changes in 2024-25
Background
This document provides some guidance for people making a submission regarding the proposed speed limit reversals on several State Highway sections. Feel free to select the content most relevant to your situations.
Everyone in our community deserves safe streets and roads.
Key Messages and Recommendations
We support the retention of currently set speed limits as they were based on:
sound road safety and environmental rationale
significant public consultation, which has always been required by the relevant version of the Land Transport Rule - Setting of Speed Limits associated with the speed limits changes
communityacceptance and in many cases strong demand for many of the speedlimit changes
Global evidence is clear that increasing speed limits is contrary to best road safety practice and contributes to worsening of air quality and heightened health impacts1.
Lower rural speeds such as 60-80 km/h and lower urban speeds such as 30-40 km/h reduce the risk and severity of crashes, especially for more vulnerable active modes.
Increasing speed limits actually has minimal impact on travel time (especially for heavy vehicles), coupled with a significant effect on safety, vehicle operating costs, and vehicle emissions.
Previous reviews of highways indicated that a 100 km/h speed limit is not appropriate for over 85% of our current state highways.
Regardless of the result of the consultation, public safety should not be subject to a vote. Rather, it should be guided by best-practice evidence.
Detailed Comments
International evidence is very conclusive that increasing speed limits exponentially increases safety risk, and that 100 km/h rural and 50 km/h urban speed limits are not the Safe and Appropriate Speeds for most rural and urban roads in New Zealand:
The risk of involvement in a casualty crash is twice as great at 65 km/h as it is at 60 km/h, and four times as great at 70 km/h2
By combining evidence from different sources, it has been estimated that speeds above New Zealand’s Safe and Appropriate Speeds are involved in around 71% of injury crashes.3
Transportation and network management is a complex system, and changes should only be made on factual, science-based evidence. The evidence since the introduction of New Zealand’s world leading Safe and Appropriate speed limit setting process is overwhelming and has saved many lives and serious injuries. Returning to 100 km/h ‘blanket’ rural speed limits is a hugely retrograde step, likely to kill and seriously injure countless more New Zealanders if it is implemented.
The following table details death and serious injury (DSI) or crash reduction benefits associated with speed limit reductions across New Zealand4. The reductions are significant and reflect the likely casualty increases if the speed limit changes were reversed, clearly showing it would be unsafe to do so. We note that some of the proposed speed limit reversals are listed below, despite the clear safety benefits since the introduction of lower limits.
Location Speed limit change made Result
Auckland rural (2020-21) 500 km reduced to 60/80 km/h 26% DSI reduction
SH2 Maramarua (2011) 25 km reduced to 90 km/h 36% DSI reduction
SH2 Karangahake Gorge (2005) 9 km reduced to 80 km/h 35% DSI reduction
Mt Maunganui (2011) 7 km reduced to 30 km/h 21% crash reduction
SH5 Napier-Taupō (2022) 75 km reduced to 80 km/h 43% DSI reduction
Hastings rural (2014) 75 km reduced to 80 km/h 32% injury crash reduction
SH58 Paremata (2005-06) 4 km reduced to 80 km/h 48% DSI reduction
Wellington suburban (2010-16) 10-15 km reduced to 30 km/h 38% crash reduction
SH60 Tasman (2018) 9 km reduced to 80 km/h 85% DSI reduction
SH6 Blenheim to Nelson (2020) 110 km reduced to 60-90 km/h 71% DSI reduction
Christchurch CBD (2016) 10 km reduced to 30 km/h 48% injury rate reduction
Christchurch suburban (2018-19) Addington/Papanui/Sumner reduced to 30-40 km/h, 59% injury reduction
SH75 Akaroa (2022) 70 km reduced to 60-80 km/h 20% DSI reduction
Invercargill rural (2022) 200 km reduced to 60/80 km/h 66% DSI reduction
The table details crash reduction benefits associated with speed limit reductions across the world5 and which reflect the same downward trends:
The risks associated with speed are even greater for more vulnerable active modes such as walking, cycling, and other forms of micro-mobility. New Zealand crash data from the past ten years quite clearly shows that the relative risk of death or serious injury to active mode users in a crash increases significantly as posted speed limits increase.
NZTA’s own commissioned research shows that the most economically efficient speed limit for our rural strategic network is not the current 100 km/h open road speed limit. An economic evaluation, published by Max Cameron and found on the NZTA website6, considered the effect of cruise speeds on the New Zealand network of each vehicle type (passenger cars and light, medium and heavy commercial vehicles) ranging from 70 to 130 km/h considering:
Crash frequencies and costs
Travel time costs, including costs for the freight industry
Vehicle operating costs
Air pollution costs
An optimum speed limit is defined as providing maximum benefit from reduced travel times and minimises the costs of road trauma, environmental emissions and vehicle operating costs. The results of the analysis confirm that 70 km/h is the optimum speed for heavy vehicles, and no more than 85km/h for light vehicles on all but New Zealand’s motorway standard roads. The overall economic impact if all vehicles travelled at their optimum speeds was estimated to be a saving of $482 million per annum in total social costs or 3.7% reduction in the estimated $13.1 billion annual cost of rural State Highway travel in New Zealand.
Specific regional/local comments added here….
CAN members are encouraged to make their own submissions and use the content drafted above to lead into their specific comments on the changes affecting them in their region (refer “Speed limit consultations across the regions” https://www.nzta.govt.nz/safety/driving-safely/speed/state-highway-speed-management/speed-reversals-and-consultation-transitional-changes-in-2024-25/ )
1 Speeding towards danger: the concerns and consequences of increasing speed limits on our roads; Christopher Wakeman, Shanthi Ameratunga, Teuila Percival, Braden Te Ao, Jamie Hosking; New Zealand Medical Journal Te ara tika o te hauora hapori; 2024 Aug 2; 137(1600). ISSN 1175-8716;
https://www.nzmj.org.nz/
2 Travelling Speed and the Risk of Crash Involvement, Volume 1 – Findings by Kloeden CN, McLean AJ, Moore VM, Ponte G, NHMRC Road Accident Research Unit, The University of Adelaide
3 Road Safety Evidence Review Understanding the role of Speeding and Speed in Serious Crash Trauma: A Case Study of New Zealand R.F. Soames Job and Colin Brodie
4 Courtesy Glen Koorey, ViaStrada, January 2025; all sites compared with similar unchanged “control” site
5 Infrastructure/Speed Limit Relationship in Relation to Road Safety Outcomes, C Jurewicz & B Turner 2010, Austroads Publication No. AP–T141/10
6 Cameron, M. H. (2022). Economic analysis of optimum speeds on rural state highways in New Zealand. Waka Kotahi NZ Transport Agency https://www.nzta.govt.nz/assets/resources/economic-analysis-of-optimum-speeds-on-rural-state-highways-in-nz/Economic-analysis-of-optimum-speeds-on-rural-state-highways-in-nz.pdf