Two expressways outside of Wellington could be getting their speed limits raised to 110km/h as Waka Kotahi NZ Transport Agency undergoes a speed management review.
It's looking at raising the speed limit on the Mackays to Peka Peka and Peka Peka to Ōtaki expressways next year.
However, the speed limit can't be raised on Transmission Gully as the road is not yet finished.
Director of regional relationships Emma Speight said a speed management technical review was being done and they hoped to decide on speed limits in early 2024.
"The review, along with public consultation, will see if it is appropriate to increase the speed limit on these expressways without compromising driver safety. We can consider increasing the posted speed limit when a road is designed and constructed to modern safety standards," Speight said.
The expressways were completed between 2017 and 2022 and include safety features such as median and shoulder barriers, two lanes in each direction and the removal of crossroads and tight curves.
These measures would reduce the risk of serious collisions.
Before these new measures of State Highway 1 were built there were over 1000 crashes on the old highway route between 2008 and 2022, Speght said.
"The number of crashes on the new expressway between Mackays Crossing and Peka Peka has fallen dramatically following its opening in 2017."
There have been 166 crashes recorded, with no fatal crashes and seven serious crashes.
"Since the opening of Peka Peka to Ōtaki Expressway last year, there have only been four minor crashes on the route," Speight said.
New higher speed limits can only be considered for roads designed and constructed to the necessary standards and only after comprehensive review and consultation.
The director of land transport at Waka Kotahi must also be satisfied the road can be safely maintained and operated at a higher speed.
Speight said the aim is to wrap this work into the State Highway Speed Management Plan 2024-27.
"This means we should be able to release a decision later in 2024. If approved by the director of land transport, we can then begin implementing any changes," Speight said.
While Te Aranui o Te Rangihaeata – Transmission Gully is also built to the same high safety and operational standards, and early indications are that the crash numbers reflect the same improvement in safety, its speed management review will not start until its remaining project works are finished.
Technical and safety reviews and public consultation would also need to be completed before any change is considered.
