ROAD SAFETY PERFORMANCES FROM MICRO-SIMULATION CONSIDERING AUTONOMOUS VEHICLES OPERATIONS

Introduction of Autonomous Vehicles in road traffic will remove the impact of the human factor from the driver’s decision-making process, and will transform the criteria for road network design, road infrastructure administration, traffic modeling and assessment tools for road safety management. The paper presents a microsimulation-based approach for safety performance evaluation of roundabouts where different percentages of Autonomous Vehicles are mixed with Conventional Vehicles. The simulated vehicle trajectories exported from VISSIM were used as a basis to estimate traffic conflicts through the Surrogate Safety Assessment Model (SSAM) for a sample of European roundabouts. In order to better consider the presence of Autonomous Vehicles in traffic and their kinematic, there has also been proposed a criterion to set the principal SSAM filters properly. The results confirmed that the safety assessment of any road unit may rely on surrogate safety measures and, in the absence of crash data which include information on Autonomous Vehicles, the simulated conflicts can be used as a promising approach for safety performance evaluation of roundabouts