The interaction of pedestrians and vehicles on urban roadways is complex. Although concerns for safety usually prevail, capacity and convenience (i.e., Quality of service) are also important considerations in the design and evaluation of transportation facilities. The effect of radius and pedestrian flows on saturation flow is of interest. These factors consequently affect the capacity of right-turn lanes at signalized intersections in which pedestrians share the crosswalk space during some portions of the green signal intervals. Canadian, Australian, and U.S. right-turn saturation flow adjustment procedures will be described, and some of the considerations being evaluated during the revision process of the Canadian Capacity Guide for Signalized Intersections (CCG) will be presented. A modification oft he saturation flow adjustment techniques included in the CCG is recommended to express the combined effect of a small radius and the presence of pedestrians on right-turn lane capacity. The proposed procedure, process and rationale leading to the development of the suggestions, and implications for the 1985 highway capacity manual are discussed.
Abstract