The case for a 30km/h speed limit in cities

As urban populations grow, city streets will overtake rural roads as the major scene of fatal traffic crashes in many countries. The evidence in support of a 30 km/h speed limit on all mixed-use urban roads is undeniable, and mounting.

Written by Stephen Perkins


International Transport Forum’s Safe Speeds YouTube Video

A lot has happened to sharpen policies for preventing deaths and serious injuries on our roads in the build-up to the Third Global Ministerial Conference on Road Safety that will meet in Stockholm on 19/20 February. The results of bold safety initiatives in a number of countries and cities have clearly demonstrated that aligning safe speeds to the design of infrastructure and the mix of road users lies at the heart of Safe System policies. Marshalling evidence on what works and what doesn’t is the key to getting public and political buy-in for these policies.

First of all, nobody any longer fatalistically regards increasing numbers of deaths on the roads of lower-income countries as the inevitable, “normal” result of increasing motorisation. The myth that death rates would only start to come down once incomes rose sufficiently has been debunked through careful review of the data by the Independent Council for Road Safety International: There is no correlation between income and peaks in road deaths.

Instead, all OECD countries saw improvement from around 1970, when their road safety policies began to be based more systematically on evidence-based, proven interventions. The powerful message here is that all countries can cut the number of deaths and injuries on the roads, regardless of GDP per capita. It also means that there is no longer an excuse: all countries must urgently implement those road safety policies that have been shown to work in their specific economic context.

Lessons from India, Colombia, France

Convincing examples of effective policies can be found in all parts of the world. Often, they were introduced in the face of vocal opposition. Pune was awarded ITDP’s Sustainable Transport Award in 2020 for doing what seemed impossible in Indian cities: establishing a sensible allocation of street space to motor vehicles to replace the chaotic free-for-all and building simple sidewalks for pedestrians.  This is the basis for safe streets and may indeed be basic. What was remarkable was creating the necessary political will by convincing the public this should be done.

Pune at night

In Colombia, the capital city Bogota is similarly making a growing number of its streets radically safer by implementing comprehensive interventions in school, residential and commercial zones, and reducing the speed limits of arterial corridors. These initiatives to promote safer interactions between all road users include the reallocation of space from cars and parking to pedestrians, often just using bold paint. But the biggest achievement has been turning around public hostility to reducing speed limits from 60 to 50 km/h on the corridors bisecting the city. By publicising the number of lives saved on these arterial roads, citizens and some of the administration’s stronger critics have accepted that speed reduction is an effective measure to save lives. 

Bold paint: pedestrian crossing in city centre

France has been in the headlines because of protests over its latest efforts to save lives by curbing speed. The policy to reduce speed limits on the fast secondary road network from 90 to 80 km/h is an outstanding example of basing policy on evidence: Evidence that shows rapidly diminishing survival rates in crashes at higher speeds; evidence that shows lower speed limits do result in lower speeds because drivers do not simply ignore limits; and evidence that shows lower average speeds always result in fewer fatal crashes.

The Safe System in action

Protests led the French Senate to modify the law, delegating responsibility for limits to Department councils. At the same time, Senators applied the Safe System principle to their decision, setting out quality and design standards to be met for 90 km/h roads. Only one Department has reinstated the 90 km/h speed limit.

This interplay between speed and infrastructure is a perfect example of the Safe System approach in action. The system has to be designed to protect against death and severe injury even when humans make mistakes. This can be achieved through controlling behaviour, improving vehicles or enhancing infrastructure, or all three – but it must be done in concert to ensure all users can use the roads safely.

Infrastructure enhancements: road works in Bogota

The basis for effective interventions is good data and analysis. The ITF supports national and city safety agencies enhance their capacity and compare their performance with our IRTAD and Safer City Streets databases. These show that the majority of traffic fatalities currently occur on rural roads, hence the importance of France’s new speed limits. Other countries need to look carefully at similar measures. At the same time, as our populations become more urban, city streets are soon set to account for the majority of casualties in ITF countries.

Safe urban mobility needs a 30km/h speed limit

The success of sustainable mobility policies will see increasing numbers of pedestrians, cyclists and electric micromobility users on our streets. This will require a redoubling of efforts to allocate space for protected cycling and pedestrian infrastructure and create mixed use roads with low speed limits. This is the front line for the safety targets under the UN Sustainable Development Goals and is taken up in Recommendation 8 of the Academic Expert Group convened to support the 3rd UN Global Conference on Road Safety. The Group recommends implementing a speed limit of 30 km/h for all mixed-use roads in urban areas. This is a true life saver, and it should be a primary focus of discussion at the conference.

An increasing number of cities have moved in this direction. Starting with 30 km/h zones in the early 1990s, almost all of Helsinki is now subject to a 30 limit. Oslo has followed suit as part of its Vision Zero policy as have Munich, Grenoble and a rapidly increasing number of cities in Europe and on other continents. With 19 cities in the 30 club, Spain is now pioneering the move at national level, with a proposal before Government for all cities to limit speeds to 30 km/h. The policy works, with Toronto reporting a two thirds reduction in serious and fatal injuries from crashes since it reduced speeds from 40 to 30 km/h in 2015. The case for making 30 km/h the default speed limit for all vehicles in urban and residential areas is clear.

Stephen Perkins is Head of Research and Policy Analysis at the International Transport Forum (ITF). The ITF runs the International Traffic Safety Data and Analysis Group (IRTAD) and the Safer City Streets network.

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