The incidence of fatal pe destrian crashes

The aim of this study was to estimate the likely effect of reduced travel speeds on the incidence of pedestrian fatalities in Adelaide, Australia. The study was based on the results of detailed investigations of 1 76 fatal pedestrian crashes in the Adelaide area between 1 983 and 1 991 . The method developed to estimate the effect of reduced travelling speed is described, and supported by references to the published literature. A reduction in the speed limit from 60 to 50 km/h was one of 26 speed reduction scenarios which were considered. The results for a selection of these 26 scenarios are presented in the paper. The smallest estimated reduction in fatal pedestrian collisions in the selection presented was 1 3 per cent, for a scenario in which all drivers obeyed the existing speed limit. The largest estimated reduction was 48 per cent for a scenario in which all drivers were travelling 1 O km/h slower. The estimated reductions in fatalities obtained in this study are compared with those observed in places where the urban area speed limit has been lowered. WALZ, HOEFLIGER AND Fehlmann (1 983) reported that the reduction of the speed limit from 60 to 50 km/h in Zurich was accompanied by a reduction of 20 per cent in pedestrian casualties and a 25 per cent decrease in pedestrian fatalities. These reductions were attributed to the change in travelling speeds caused by the change in the speed limit. The number of pedestrians with ISS scores greater than 30 decreased, with the mean ISS decreasing from 28 to 20. The incidence of fractures to the pelvis and ribs were reduced by 50 per cent. Those who were fatally injured also had fewer fatal injuries. In 1 8 per cent of the crashes the collision speed was equal to the travelling speed of the striking vehicle, but in 62 per cent the collision speed was reduced to at least one-fifth less than the travelling speed. Fieldwick and Brown (1 987) studied the road crash fatality and casualty rates of 21 countries to develop a regression model based on population, the number of vehicles and the posted speed limits in both urban and rural areas. They concluded that those countries which have an urban speed limit of 60