Surrogate safety evaluation of a multimodal combined alternate-direction lane assignment and reservation-based intersection control

The concept for management of directionally unrestricted traffic flows in urban areas called Combined Alternate-Direction Lane Assignment and Reservation-Based Intersection Control (CADLARIC) has been recently developed. CADLARIC concept aims to optimize traffic flow in urban areas by efficiently managing directionally unrestricted traffic flows, thereby reducing congestion and improving overall traffic efficiency. The main idea behind CADLARIC is to organize traffic flow in the connected and automated vehicles environment and distribute vehicular conflicts between links and intersections to prevent intersections from turning into traffic bottlenecks. In the proposed concept, vehicles can use lanes traditionally reserved for the opposite direction of travel. Through its reservation-based algorithm, CADLARIC effectively manages conflicts for through vehicles, ensuring seamless passage and minimizing delays at intersections. However, CADLARIC in its current state is only based on vehicular flow and does not include pedestrians. Adding pedestrians impacts traffic flow efficiency and introduces additional conflicts which are handled on a Pedestrian Priority basis. Pedestrians reserved their path when attempting to cross at intersections, thereby inflicting the behavior of vehicles within the simulation. In this paper we evaluated safety of CADLARIC in comparison with Fully Reservation-Based Intersection Control with conventional lane assignment (FRIC), and Fixed Time Control. The findings indicate that the CADLARIC control strategy demonstrates significant potential for enhancing intersection safety. It surpasses the FRIC control scheme in terms of safety performance, particularly under conditions of increased vehicular and pedestrian demand, as evidenced by improvements in all surrogate safety measures analyzed in this study.