Introduction of autonomous vehicles: roundabouts design and safety performance evaluation

Driving experiences provided by the introduction of new vehicle technologies are impacting directly the criteria for road network design. New criteria should be taken into consideration by designers, researchers and car owners in order to assure traffic safety in changed conditions that will appear with, for example, introduction of Autonomous Vehicles (AVs) in everyday traffic. In this paper roundabout safety level is analysed on originally developed microsimulation model in circumstances where different amount of AVs vehicles are mixed with Conventional vehicles (CVs). Field data about speed and traffic volumes from existing roundabouts in Croatia were used for development of the model. The simulations done with the Surrogate Safety Assessment Model (SSAM) give some relevant highlight on how the introduction of AVs could change both operational and safety parameters at roundabout. To further explore the effects on safety of roundabouts with the introduction of different share of AVs, hypothetical safety treatments could be tested to explore whether their effects may change, leading to the estimation of a new set of Crash Modification Factors.