An-Najah Staff

Existing manuals do not provide clear specifications regarding the required crosswalk width under various pedestrian demand combinations and properties. Furthermore, they don’t offer any quantification regarding the effects of bi-directional flow and pedestrian flow composition upon capacity. This paper analyzes the effects of pedestrian age group and the interaction between bi-directional pedestrian flows on the capacity of signalized crosswalks. Three pedestrian age groups are defined: middle-age, pupils and elderly. A previous developed methodology for modeling pedestrian flows at signalized crosswalks is utilized to generate the fundamental diagrams of pedestrian flow. It is found that the maximum reduction in capacity occurs at roughly equal pedestrian flows from both sides of the crosswalk. Further, it is concluded that elderly pedestrians might cause a significant reduction in capacity up to 30%. © 2011 Published by Elsevier Ltd.

Among various pedestrian facilities, signalized crosswalks are the most complex and critical ones. Their geometry and configuration including width, position and angle directly affect the safety, cycle length and resulting delays for all users. Existing manuals do not provide clear and rational specifications for the required crosswalk width under different pedestrian demand combinations and properties. Furthermore, they do not consider the bi-directional flow effects on crossing speed and time when addressing pedestrian flow at signalized crosswalks. However, quantifying the effects of such interactions on the behavior of pedestrian flow is a prerequisite for improving the geometric design and configuration of signalized crosswalks. The objective of this paper is to develop a methodology for estimating the required crosswalk width at different pedestrian demand combinations and a pre-defined LOS. The developed methodology is based on theoretical modeling for total pedestrian platoon crossing time, which consists of discharge and crossing times. The developed models are utilized to generate the fundamental diagrams of pedestrian flow at signalized crosswalks. A comprehensive discussion about the effects of bi-directional flow and various pedestrian age groups on the characteristics of pedestrian flow and the capacity of signalized crosswalks is presented. It is found that the maximum reduction in the capacity of signalized crosswalks occurs at roughly equal pedestrian flows from both sides of the crosswalk. By utilizing existing LOS thresholds for pedestrian flow at signalized crosswalks, the required crosswalk widths for various pedestrian demand combinations are proposed for implementation.