Red light violations (RLV) have been an ongoing concern to many engineering professionals, since a large portion of crashes that occur at urban signalized intersections involve the running of red lights and often result in injuries and fatalities. It has been estimated that in the United States, approximately 260,000 traffic crashes occur per year that involve drivers who run red lights, of which 750 are fatal (1). The purpose of this study was to perform a "before and after" evaluation of the impacts of a clearance interval, calculated according to the Institute of Transportation Engineers (ITE) guidelines. The study included three signalized intersections located in Oakland County, Michigan, one of which includes a divided suburban arterial, the second has a boulevard on its minor street and the third is a typical undivided roadway intersection. Red light violation data was collected using standard video cameras at intersection approaches before and after, the implementation of the clearance intervals calculated according to the ITE recommendations. The RLV and late exit data was extracted by trained researchers in a laboratory. The results of the 'before' and 'after' study indicated that at the three study intersections, the clearance intervals calculated as per ITE's recommendations, were effective in reducing red light violations. Additionally traffic crash comparison performed before and after the implementation of the clearance intervals at the three study intersections showed reductions in right-angle, injury and total crashes.
Samenvatting