Reexamining Pedestrian Crossing Warrants based on Vehicular Delay at Urban Arterial Midblock Sections under Mixed Traffic Conditions

Abstract

Pedestrian crossing activity at unmarked crosswalks on urban roads in developing countries like India is a common phenomenon. Pedestrians used to cross the road at their place of interest to access residential and commercial land use. Such crossing operations cause a twofold effect: first the pedestrian put themselves at high risk of collision with the moving traffic, and they also affect the normal traffic operations, which causes excessive delay to vehicular traffic. Available pedestrian crossing warrants (PCWs) based on PV2 (where P is the volume of crossing pedestrians per hour and V is per-hourly traffic volume) focus on the safe movement of pedestrians, but traffic operation is least considered in such warrants. The present study deals with the development of pedestrian crossing facility warrants based on pedestrian safe movement along with vehicular delay, which includes traffic efficiency as well. The traffic data collected from four different locations through the videographic survey were used for evaluating the delay for the individual vehicle due to pedestrian crossing activity. The delay thus evaluated was further validated using the probe vehicle data collected during the same observation period. The vehicle was fitted with the GPS-based performance box instrument that provides the vehicle trajectory at any instance. A significant number of sample data were collected with the probe vehicle and delay was determined using trajectory data. The finding of the delay obtained from the field data was validated incorporating a simulation-based analysis to resemble the interaction of pedestrian flow dynamics with vehicular flows. The crossing behavior of pedestrians was simulated using microscopic simulation software VISSIM. The microsimulation model was first calibrated and validated for field traffic conditions. The total delay was assessed for the traffic stream, and it was found to follow a second-degree polynomial relationship with PV2 values. The clustering analysis was carried out using K-means clustering to define a threshold value for pedestrian crossing facilities. These warrants were also identified based on PV2 utilizing the relationship between total delay and PV2 values. The results of the present study will be useful for practicing engineers for designing pedestrian crossing facilities considering pedestrian safety and vehicular operation as well.