An investigation of the effect of accident frequency of the priority rule at roundabouts has indicated that during its first 18 months operation the numbers of fatal and serious casualties at the ordinary roundabouts where the rule applied were unaffected by its introduction. The layout of some roundabouts precludes the application of the simple priority rule and at these special road markings and signs are used. It was suggested that these departures from the general rule might not be in the interests of road safety. Investigation of 55 roundabouts where such markings were used has shown that the number of injury accidents was about 18 per cent fewer than expected based on national trends; at these sites total casualties were 16 per cent fewer and fatal and serious casualties combined were 32 per cent fewer. (Author/publisher)
Abstract