Moving forward with speed management, and not backwards, is needed to save lives.

By Hamish Mackie & Sam Pasley

New rules for setting speed limits have been indicated by government, with the goal of reversing the approach to safer speeds set by the previous government. The Australasian College of Road Safety, the pre-eminent voice of road safety evidence and expertise across Australia and New Zealand, has a policy position statement on speed management, and is calling for an agreed and evidence-based approach to setting speed limits.

A stubbornly high number of people are killed or seriously injured on New Zealand roads, and according to the OECD New Zealand ranked 29th out of 35 OECD countries for road fatalities per 100,000 inhabitants in 2022, a step worse than Greece and a little better than Serbia. Beyond the statistics, there are countless stories of loss, avoidable harm and heart ache, and a frustratingly consistent yearly story across Aotearoa, most recently when five people were killed in a head-on crash in the Waikato.

We are usually quick to point to the errors drivers make and, in some circumstances, reckless behaviours such as drink driving can be the primary cause. But research shows that around half of fatalities on our roads involve everyday people, doing everyday trips, just making a simple mistake. We all make mistakes now and then, but if they happen on an undivided road at 100 km/h, the result will likely be fatal.

Speed management has been proved to save lives. The evaluation of 880 km of Auckland roads that were subject to Phase 1 of the Safe Speeds Programme found a 30% reduction in fatalities (compared with a 9% increase in fatalities where speeds were not changed), and a relative reduction of 18.4% for all injuries. An evaluation of rural speed limit reductions from 100 km/h to 80 or 90 km/h at appropriate locations in the Waikato have also led to reductions of deaths and serious injuries of around 30%.

Speed limits stir many opinions and many worry that they’ll be slowed down or lose productivity with lower speed limits. In fact, where lower speed limits have been implemented, overall travel times usually stay about the same. This is because most people are already travelling slower due to intersections or cornering, and the lower speed limit just gives a clearer message to those driving too fast for the conditions. Furthermore, road crashes cost the country in productivity, approximately $10B per year (or 4% of the GDP). One of the worst things we can do for productivity is kill and seriously harm our young people who have a lifetime of societal contribution and productivity ahead of them – road crashes are the leading cause of death of New Zealand’s young people.

Understandably, some people find changes in speed limits confusing where the road context doesn’t match. This is important and it’s key to the ACRS speed management position statement. Speed limits need to be set to reflect different road types. Slower streets near schools and shopping centres have many pedestrians even outside of busy times and we know that the risk of a fatality increases dramatically above 30 km/h when a vehicle collides with a pedestrian or cyclist. On higher speed roads where there is a risk of head-on collisions, even the safest vehicles won’t prevent fatalities or very serious harm when speeds are above 70 km/h. So if we are serious about saving lives on the road, we need our speeds to reflect peoples vulnerability in different contexts. It’s really important speed limits are credible and believable, and reflect the risk.

Most importantly, if we want to make progress in driving down harm on our unsafe roads, safer speed limits that match the conditions and make sense are by far the most cost-effective way to do this. Enforcement of non-compliant behaviour is certainly important, but all parts of the system need to play their part. We need our vehicles, our roads, our road users, and our speed limits to be safe if we are to expect any improvement in the unnecessary and costly trauma and loss of opportunity that hundreds of families and friends experience each year.

The next steps for speed management should reflect evidence and lessons learned, with corresponding improvements. As a country we need to accept that many of our roads are not safe with their lack of safety features and relatively high speeds. Reversing safer speed limits where they are working, where many communities have asked for them, like around town centres, schools, quiet community streets, and on difficult rural roads would be a backward step. The evidence clearly shows that this will lead to more deaths and harm on New Zealand roads. We have a growing evidence base for how well implemented speed limit reductions that make sense to people in different situations have saved lives.

Over coming years it will be important to robustly monitor the outcomes from speed management activities so that progress can be tracked and built-on, and likewise any worsening of harm can be explained.

About Hamish Mackie
Hamish is co-director of Mackie Research and has 24 years of research and consultancy experience in various areas of human factors and ergonomics, with the last 18 years spent mostly in the transport sector. Hamish is also an active member of the New Zealand Chapter of the Australasian College of Road Safety.

About Sam Pasley
Sam is a Chartered Professional Road Safety Engineer in Safe System Solutions’ New Zealand office. Sam has over 15 years’ experience in road safety and transport engineering and has previously led a team of over 25 road safety professionals. Sam is also an active member of the New Zealand Chapter of the Australasian College of Road Safety.