Installation of traffic calming measures is the responsibility of the relevant local highway authority.
Traffic calming provides a proven and effective way of saving lives and reducing casualties. Its primary purpose is to reduce vehicle speeds in areas where inappropriate speed is a problem. It plays an important role in improving road safety, and each 1 mph reduction in vehicle speed resulting from traffic calming has been found to reduce accidents by around 5%.
Traffic calming has been the subject of extensive research. The Department publishes advice for local authorities on designing and installing traffic calming, in Local Transport Note 1/07: Traffic Calming, available at https://www.gov.uk/government/publications/traffic-calming-ltn-107. This brings together a summary of the research commissioned by the Department and its predecessors, together with some research from external sources, to provide advice on the use of traffic calming measures today.