Back to school for the Govt’s new speed limit policy

The Government recently released the draft Land Transport Rule – Setting of Speed Limits 2024, which would force councils to raise many urban 30kph speed limits to 50kph, as well as removing permanent low-speed zones around schools.

The latest attack by the Government on city speed limits is a giant step backward, for three reasons.

First, this overrides the wishes of communities all over New Zealand who want slower, safer residential streets. Permanent low-speed zones, for instance, were supported by 78 percent of school leaders in Tāmaki Makaurau’s recent speed-management plan consultation and will be abolished if the new Land Transport Rule is adopted. Permanent speed limits were supported by close to 80 percent for good reason: these are more effective than variable speed limits at preventing deaths and injuries, and cheaper to implement.

The move contradicts what the coalition parties campaigned on, the theme of less big government and more local decision-making. But now Simeon Brown, the transport minister, claims he knows best, or at least better than what school leaders or the people who live close by and use their local streets.

Second, there is a mountain of evidence that higher speeds lead to more traffic crashes, injuries and deaths. A summary of 20 high-quality studies found the risk of pedestrian death increases tenfold when vehicle speeds rise from 30kph (5 percent mortality) to 60kph (when impact is associated with only a 50:50 chance of survival).

Third, the Government is moving in the opposite direction from that taken by other countries we like to compare ourselves with.

On the Act website, the party claims that ‘all over the country speed limits are being cut to a crawl’ and ‘after thousands of years of human history, we are the first society ever to try going slower’. We don’t know where the party got that idea – because it’s not true.

The first 20mph (32kph) city limits were introduced in the United Kingdom in the 1990s (in Sheffield, Kingston-upon-Thames and Norwich). Case studies of lower speed limits in America have been published from Seattle, New York, Cambridge, and Portland. A recent paper identified new 30kph speed limits in 40 European cities, including Brussels, Paris, and Zurich.

If New Zealand is a world leader, it’s because we haven’t been able to find any other example of a high-income country that has recently raised urban speed limits.

When speed limits were reduced in New Zealand in recent years it wasn’t for the first time.

Highway speed limits were reduced in the 1970s in many countries in response to oil shortages, including in New Zealand where the speed limit on the open road was lowered in November 1973 from 60mph (96 kph) to 50mph (80kph). The following year the number of fatal road crashes on the open road fell by 37 percent, compared with a 15 percent reduction in urban areas, in which there were no changes to speed limits. In the United States there was a similar pattern: road crash deaths on interstate highways fell after stricter speed limits were reduced, and increased by 4-9 percent when the speed changes were reversed roughly a decade later.

New Zealand could learn from the experience of countries that introduced and maintained 30kph speed limits in urban areas. It would be a sensible place to start, surely, with the evidence.

The review of 40 European cities published this year indicated that reductions in speed limits improved road safety by decreasing the likelihood of crash risk and the severity of crashes that do occur. On average, the implementation of 30kph speed limits in European cities demonstrated a 23 percent, 37 percent, and 38 percent reduction in road crashes, fatalities, and injuries. The study also demonstrated environmental benefits, with reduced pollution (tail-pipe emissions down by 18 percent) and noise (2.5dB less, on average) and improved fuel consumption (by 7 percent).

Contrary to what our politicians might tell us, we’ve found no evidence that 30kph speed limits make a big difference to congestion – numbers of cars on the road, intersections, traffic lights and vehicle size are more important influences on travel times. (With large vehicles, fewer pass through each traffic light cycle.) Much has been written about the introduction of 20mph speed limits in London, limits that apply to about half the roads in the city. Transport for London reports that collisions on treated streets resulting in death or serious injury have fallen by 25 percent, and travel times have changed little.

Low-speed zones (such as the ‘mini-Hollands’ in London, which reduce speeds for entire neighbourhoods) tend to be more effective than speed limits on isolated stretches of road. Evaluation of low-speed zones report substantial and consistent reductions in speed and more frequent cycling and walking, changes that tend to be associated with more people on local streets, improving safety and the fortunes of local business.

The draft Land Transport Rule amounts to forcing communities, against their wishes, to accept more deaths and serious injuries on neighbourhood streets and around schools. It’s this law change that should be reversed, not our safe speed zones.