Speed limit reductions in built-up areas: Effects on speed and accidents

This working report considers studies regarding reduction of speed limits to 40 km/h and 30 km/h, traffic calming measures and road humps. Each of the studies is considered regarding effects on accidents and speed. The effects on other behaviour, mobility and environment are described if reported. All studies are accident studies and the effects on accidents have been calculated by using meta-analysis. Traffic calming measures and road humps are the measures that are studied most. Considering studies that include control groups only, their effects on casualties are calculated to 18% and 37% respectively. These measures seem to achieve accident reductions of 3,5% and 4,5% respectively for each km/h the speed is reduced.