In most developed countries accidents in urban areas tend to fall into two categories; those clustered at specific sites, and the rest scattered throughout the area. This paper describes a large scale experiment which attempted to demonstrate that scattered accidents could be reduced by broadly applying low cost safety measures on an area-wide basis in five towns. The objectives were to help traffic use main routes more safely, discourage the use of residential roads for through traffic, and create safer conditions in residential areas. The objectives were achieved by analysing accidents and flow in each area and defining a road hierarchy. Measures were then installed to ensure only suitable ensure only suitable traffic used each type of road. Overall accident reductions of 13% were measured. Reducing speeds on residential roads is an important factor in enforcing the road hierarchy and creating safer conditions. Experience shows that low (20 mph) speed limit restrictions will only work where engineering measures are designed and installed to keep speeds low. (A)
Abstract