The implementation of 30km/h speed limits in numerous European cities has yielded significant benefits for residents, with no meaningful impact on travel times, a new study has concluded.
In recent years, major cities including Paris, Zurich, Amsterdam, and Brussels have lowered the default speed limit in an effort to make streets safer and quieter. The Welsh government recently applied the same policy wherever cars mix with pedestrians and cyclists.
The new paper, compiled by researchers at the National Technical University of Athens and published in the peer-reviewed journal Sustainability, looked at a number of metrics from 40 cities that have gone this route.
It found that the shift to 30km/h speed limits had led to a 37% decline in road crash fatalities, an 18% reduction in emissions, a 2.5 decibel decline in noise pollution, and a 7% fall in fuel consumption, on average.
The trade-off, generally, is only a “very small” variation in average traffic speed, according to the study.
In fact, travel times are sometimes improved given that traffic flows most smoothly at speeds of 20–30 km/h in urban centres, the authors say. That’s partly because this speed range facilitates the entry of traffic from side streets, ensuring continuous flow.
Traffic data from Switzerland revealed that 30 km/h limits “allowed the road system to accommodate more cars efficiently, resulting in faster overall travel times.”
The authors argued that to maximise the benefits, reduced speed limits should be coupled with investments in public transport as well as cycling and pedestrian infrastructure.
