Consideration of a Pedestrian Speed Change Model in the Pedestrian-Vehicle Safety Assessment of Signalized Crosswalks

Pedestrian safety is one of the most challenging issues in the road network. Understanding the pedestrian maneuver is the key to applying countermeasures against traffic crashes. It is known that behaviors of pedestrians at signalized crosswalks are significantly different from ordinary walking spaces and they are highly influenced by signal indication, potential conflicts to vehicles and intersection geometries. One of the most important characteristics of pedestrian behavior at crosswalks is the possible sudden speed change while crossing. Such sudden behavioral change may not be expected by conflicting vehicles, which may lead to hazardous situations. This study aims to quantitatively model the pedestrians' sudden speed change maneuver at signalized crosswalks under uncongested conditions. Pedestrian speed profiles are collected from empirical data and speed change events are extracted assuming that the speed profiles are stepwise functions. The occurrence of the speed change events is described by a discrete choice model as a function of the necessary walking speed to complete crossing before red interval, current speed, and the presence of turning vehicles in the conflict area. The amount of speed change before and after the event is modeled using regression analysis. A Monte- Carlo simulation is applied for the entire speed profile of the pedestrians. The results showed that the model was able to represent the pedestrian travel time distribution more accurately than the constant speed model. � 2017 The Author(s).Scopu