Level-of-Service Model for Pedestrians at Signalized Intersections

Abstract

This paper documents a study performed to develop a level-of-service (LOS) model that accurately represents pedestrians’ perceptions of crossings at signalized intersections. This model incorporates perceived safety and comfort (i.e., perceived exposure and conflicts) and operations (i.e., delay and signalization). Data for the model were obtained from an innovative Walk for Science field data collection event and video simulations. The data consist of ( a) participants’ perceptions of safety, comfort, and operations as they walk through selected signalized intersections and ( b) the design and operational characteristics of these intersections. The resulting model provides a measure of the pedestrian's perspective on how well an intersection's geometric and operational characteristics meets his or her needs. The pedestrian LOS model for intersections described in this paper is based on Pearson correlation analyses and stepwise regression modeling of approximately 800 combined real-time perceptions (observations) from pedestrians walking a course through signalized intersections in a typical U.S. metropolitan area. The resulting general model for the pedestrian LOS at intersections is highly reliable, has a high correlation coefficient ( R2 = .73) with the average observations, and is transferable to the majority of metropolitan areas in the United States. Primary factors in the pedestrian LOS model for intersections include right-turn-on-red volumes for the street being crossed, permissive left turns from the street parallel to the crosswalk motor vehicle volume on the street being crossed, midblock 85th percentile speed of the vehicles on the street being crossed, number of lanes being crossed, pedestrian's delay, and presence or absence of right-turn channelization islands.