Accidents at 3-arm traffic signals on urban single carriageway roads

The report presents the findings of a study of accident risk based on a national stratified sample of 221 3-arm traffic signal junctions. The study involved 2262 injury accidents occurring between 1985 and 1991; the junctions were on single-carriageway roads subject to a 30 mph speed limit. Accident tabulations are given of frequencies, rates, and severity, and include disaggregation by type, region, road user involvement, and time period. The main objective of the study was to develop relationships between accident frequency and explanatory variables and factors - including vehicle and pedestrian flows, junction features and geometry, land use, and signal control characteristics. The technique of generalised linear modelling was used to develop such relationships for different types of accidents. (A)