Pedestrian Crossing Sight Distance: Lateral Clearance Guidelines for Roadways

Abstract

No design guidelines are available for pedestrian crossing sight distance (PCSD) and associated lateral clearance on roadways. Guidelines are available only for intersection (vehicle) sight distance (ISD) at two-way stop-controlled (TWSC) intersections. This paper presents a new model for pedestrian crossing time that is used to establish a general model for lateral clearance at crossings located on curved (or straight) roadways. The model is applicable to all crossing types: TWSC intersections, midblocks, and freeway ramps. The model can be used to determine the maximum lateral clearance to the right or to the left of the crossing or the required lateral clearance at a specified location. The distance from the crossing within which on-street parking should be restricted to satisfy PCSD is also determined. A single spreadsheet that is applicable to all crossing types was developed. A comparison with ISD shows that lateral clearance needs for pedestrians are not satisfied by those currently available for vehicles. Design aids for all crossing types are presented. The method presented in this paper promotes pedestrian safety and should be of interest to the highway community.