In this opinion piece, Timothy Welch, Senior Lecturer in Urban Planning at the University of Auckland, argues that the government’s push to raise speed limits on roads is both unsafe and financially unwise.

Despite expert warnings and evidence showing the benefits of slower speeds, the government is moving ahead with its plan.

Welch points to documents released by the New Zealand Transport Agency (NZTA), which show concerns raised by Land Transport Director Brent Alderton.

Alderton warned in 2024 that decisions should be based on evidence, not ideology, especially since research links higher speeds to more crashes and worse outcomes.

A report by consulting firm WSP, released under the Official Information Act, highlights the economic benefits of reduced speed limits.

It found that lower speed limits led to 27 fewer deaths and serious injuries annually.

For every dollar spent on slightly longer travel times, New Zealand saved between NZ$2 and $10 in crash costs.

Despite this evidence, the government insists that raising speed limits will boost productivity by reducing travel times.

However, Welch argues that any productivity gain is outweighed by the increased costs of crashes.

The Ministry of Transport estimates that serious injuries cost NZ$769,400 each, and fatalities cost NZ$14,265,600.

Welch also points to data showing that speed limit reductions led to fewer accidents than expected.

For example, the Blenheim to Nelson stretch of State Highway 6 saw an 82% reduction in deaths and injuries, far more than the 22% predicted.

Similarly, increasing speed limits in Waikato led to a 133% increase in serious accidents.

In Auckland, speed limits are set to rise from 50 km/h to 60 km/h on several urban roads, and from 60 km/h to 80 km/h on a few key roads.

Welch warns that these increases could lead to more crashes and injuries, pointing to the evidence of higher crash risks when speed limits are raised.

Timothy Welch argues that lower speed limits are safer and more cost-effective.

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