Transport Minister Simeon Brown announced a lift for the Kāpiti Expressway speed limit, from 100kph to 110kph. Video / Mark Mitchell
The Government has sought feedback on 120km/h speed limits for new highways.
NZTA says this speed limit would make roads more expensive to build and require new standards.
Transport Minister Simeon Brown says no decisions have been made yet.
NZ Transport Agency Waka Kotahi has warned roads with 120km/h speed limits would be more expensive to build and require new safety and engineering standards.
The Government is pushing ahead with a new speed limit rule to enable motorists to travel 110km/h on new and existing “roads of national significance” where they are built to a high safety standard.
Transport Minister Simeon Brown told the Herald that of the 4874 submissions received, just over half supported enabling the 120km/h speed limit and just under a third opposed it.
Many places across the world have speed limits on motorways that are 120km/h or more, Brown said.
“For example, according to the European Commission, the most common default speed limit on motorways across the European Union is 130km/h. This limit exists in 14 out of 27 countries within the EU.”
Brown received advice in June from NZ Transport Agency Waka Kotahi (NZTA) about what it would have to consider as the road controlling authority for motorists to travel at 120km/h. This advice has been released to the Herald under the Official Information Act.
NZTA said current safety and engineering standards do not cover 120km/h speed limits and noted the maximum speed for motorway design in Australia was 110km/h.
This meant new safety standards would need to be prepared.
NZTA said roads would generally cost more to construct to support the 120km/h limit because they would need to be straighter, flatter and have wider shoulders for visibility.
More earthworks would be required on the crest of hills and wider spacing for interchanges, the advice said.
Safety issues were also identified.
“Increased speed reduces the width of a driver’s visual field and peripheral vision, significantly compromising their ability to recognise hazards and increases the distance travelled to react to that hazard at higher speeds,” NZTA said.
“Reduced ability of road users to judge vehicle speed and time before a crash and less opportunity for other road users to avoid a crash, increases likelihood of crashes.”
Transport Minister Simeon Brown and the Government have proposed raising the speed limit along sections of the motorway north of Auckland to 110km/h. Photo / Sylvie Whinray
Safety barrier systems were currently only tested up to 100km/h with a 10-tonne vehicle for wire rope and 90km/h with a 36-tonne truck for concrete, NZTA said.
There are barrier systems internationally that can support higher road speeds but there are currently none in New Zealand.
Energy in crashes increased by 20% over 100km/h and 44% over 110km/h, the advice said.
AA road safety spokesman Dylan Thomsen said it would be a significant task to change current standards to accommodate a 120km/h speed limit.
“There are a huge amount of rules and engineering detail about what is required for different types of roads and it would be a big thing in our view to look at putting together new standards for what you would need to build to.
“There are none in Australia or New Zealand at this point so it would be a completely new category.”
There was not a universal design standard for speed limits, Thomsen said.
However, highways constructed in New Zealand recently have been built to the same 110km/h engineering standard applied in many countries, he said.
For example, Kāpiti Expressway, which opened in 2017, currently has a 100km/h speed limit despite it being built to a standard that can accommodate 110km/h.
Last week the Government announced the limit would be lifted to 110km/h by the end of November.
Consultation has now also started on 110km/h speed limits for the Northern Gateway Toll Road, Pūhoi to Warkworth and the Christchurch Southern Motorway.
Brown said if the 120km/h limit was enabled for new roads, NZTA would be responsible for ensuring there was a standard to support it and one that could be delivered cost-effectively.
“As Minister of Transport, I want to enable people and freight to get to where they want to go quickly and safely. The roads of national significance projects, which began under the National Government in 2009, are some of the safest roads ever built in New Zealand.”
Brown said he was finalising the Government’s new speed rule to reverse Labour’s “blanket speed limit reductions” and enable 110km/h speeds on roads of national significance from the day they opened.
No decisions have yet been made about increasing speed limits to 120km/h, Brown said.
Thomsen said the Government should focus on the standards New Zealand already has.
“Especially at a time when our transport budget is stretched and we need to put significant investment into upgrading and maintaining the road network that we’ve already got in the country.
“We think it would be better to focus more on work that’s going to have highways at 100km/h or 110km/h limits rather than spending more to have a few stretches at 120km/h.”
Georgina Campbell is a Wellington-based reporter who has a particular interest in local government, transport, and seismic issues. She joined the Herald in 2019 after working as a broadcast journalist.
