This project was undertaken to develop a new all-way stop policy that would, with success and credibility, select intersections best suited to all-way stop controls. A variety of categories is considered by the new policy: accidents, unusual conditions, traffic volumes, and pedestrian volumes. Each category contributes points to a total that may, in sum, justify all-way stops for the intersection. Conversely, the circumstances within one category may be sufficiently extreme as to justify all-way stops based on that category alone. Existing all-way stop policies were determined to not be sufficiently flexible. The new policy combines the best features from national policies and the old city of San Diego policy. Also, the provisions within the new policy are derived from research and experience with all-way stops, not simply modifications of traffic signal warrants. The policy was tested by comparing accidents and field performance in a before-and-after study of existing all-way stop intersections. Some of these intersections met the all-way stop criteria in the new policy, whereas others did not. The study showed convincingly that the intersections that met the new policy's criteria had fewer accidents and stop sign violations than the intersections that did not.
Abstract