Efficiency and safety assessment of suburban highway access management

Congestion and traffic accidents often take place at the entrances and exits of highways. However, reasonable access management and design can greatly mitigate congestion and accidents. This paper discusses the field of suburban highway access management by introducing three typical suburban highways access management models, including the two-way stop-controlled intersection, simplified restricted crossing U-turn (RCUT), and interchange with right-in right-out. To ensure better efficiency and safety, the simulations were conducted in VISSIM and Surrogate Safety Assessment Model (SSAM) software. The travel time, delay, and throughput are used as the efficiency indexes, and the traffic conflicts are used as safety indexes to quantify the access management performance. The results show that the total delay at an interchange with right-in right-out decreased by 40.5%, and the conflict decreased by 50.0% more than a two-way stop-controlled intersection design, as well as the total delay decreased by 30.7% and the conflict decreased by 67.4% more than a simplified RCUT design.