Urban street performance: Level of service and quality of progression analysis

Effective design and evaluation procedures are essential in optimizing the performance of urban arterial streets. Current procedures rely on Highway Capacity Manual (HCM) tools for performance evaluation. Determination of level of service (LOS) on urban streets is based on urban street classification and average travel speed on the arterial. Average travel speed is computed from length of street segments and running times, which include control delay of through movements at signalized intersections. Studies have shown the inadequacies of the existing HCM procedure to take into account effects of coordination or lack of it. This paper introduces new approaches for improved quantification of the quality of progression by using the previously developed cyclic coordination function in conjunction with the HCM procedure. This enables determination of LOS on an urban street in a more systematic and accurate manner. Alternative LOS procedures for signalized urban street systems are presented. Both one-way and two-way street configurations are considered.