A method to calculate the change interval duration to ensure pedestrian safety

Abstract

Abstract An analysis of effective principles and proposals to determine the duration of the traffic lights change interval is carried out. The traffic lights cycle consists of green and change intervals. The green interval resolves the issue of the street-and-road-network traffic capacity at junctions, and the change interval provides traffic safety. Its purpose is to rule out the situation when different conflicting flows come to one point at the same time. The existing approaches resolve the issue of spatial and temporal separation of conflicting flows of vehicles only, thus reducing the change interval duration to the period of yellow light activation equal to 3 s. This approach together with the ambiguous wording in the Road Traffic Regulations (RTR) regulating the order of pedestrian entering the trafficway at controlled crosswalks does not provide pedestrian safety. On the one hand, the effective RTR allow vehicles to complete passing intersections when drivers have no capability to stop in places listed in Item 6.13 of the RTR (in particular, in front of the stop line). This leads to vehicle approaching the crosswalk as a conflicting flow facing the red light. On the other hand, other requirements set forth in the RTR allow pedestrians to enter the trafficway (at controlled crosswalks) starting with the moment of green light switching-on. Issues connected with drawbacks of the effective RTR lead to a conflict between vehicles finishing passing the controlled intersection and pedestrians starting moving following the green light. A method for calculating the duration of the traffic lights change interval for a specific direction, providing pedestrian safety, is developed.