Lower speeds good for lives and environment

Setting a 30km/h speed limit would make cities a lot safer while effectively reducing carbon emissions. Plus, you would not […]

Setting a 30km/h speed limit would make cities a lot safer while effectively reducing carbon emissions. Plus, you would not even have to be late for work.

Being hit by a car travelling at 50km/h corresponds to falling from the third floor of a building. One has only 50% chances of surviving the crush. On the other hand, being hit by a car running with 30km increases chances of survival as 95%. Yet the former is the general speed limit in European cities, with only some zones and streets as exceptions.

Needless to say, if you had to jump, you’d choose the first floor.

This could be reason enough to reduce the general speed limit in cities to 30 km/h, but there’s more. In fact, going at lower speeds could also contribute to saving CO2 and other emissions.

As a group of researchers around Jesus Casanova from the Global Network for Environmental Science and Technology has found out, reducing the speed limit to 30 km/h on city streets does not only have no impact on the time it takes to complete a trip by car, but also reduces harmful emissions from cars because less fuel is being burned.


The results show that by reducing the speed limit from 50 km h-1 to 30 km h-1, using a normal driving style, the time taken for a given trip does not increase, but fuel consumption and NOx, CO and PM emissions are clearly reduced. Therefore, the main conclusion of this work is that reducing the speed limit in some narrow streets in residential and commercial areas or in a city not only increases pedestrian safety, but also contributes to reducing the environmental impact of motor vehicles and reducing fuel consumption. In addition, there is also a reduction in the greenhouse gas emissions resulting from the combustion of the fuel.

The researchers conclude that reducing the speed limit is not only an efficient way to make pedestrians safer, but to help the environment as well.

Thus setting a 30Km/h speed limit is one of the measures promoted by the European Mobility week campaign which motto is “Clean air-it is your move”.  Reducing emissions AND getting more people on bicycles thus less in cars, the 30K option appears almost as a magic trick.

ECF has long campaigned for lower speed limits in cities and supports the European-wide 30K campaign for a 30 km/h speed limit in cities. Changing the default speed limit is much cheaper for cities than implementing a 30K zone as it doesn’t need any infrastructure or signposting work.

About Heinrich

Promoting everyday cycling