Investigating the Impact of Autonomous Vehicles on Roundabout Performance Using Microsimulation

The rise of autonomous vehicles (AVs) promises a revolution in traffic operations, due to their overall context-awareness, improved performance, and reduced crash rates. They present an ideal arena to investigate their potential impact on various traffic flow characteristics. This research investigates how increasing AVs market penetration affects operational performance at a two-lane roundabout via a microsimulation environment. Key performance measures, such as delays, number of stops, and queue length are reported. Turning movements at the studied roundabout were collected and modeled in the simulation environment to create morning and evening peak period reference cases. Five scenarios are simulated, gradually introducing AVs into the traffic stream from 0% to 30%. The results reveal significant performance improvement as the AVs penetration level increases. Delays are reduced by up to 25% at high penetration rates. This translates to substantially fewer stops and shorter queues, with reductions exceeding 30% and 50%, respectively. While this research illustrates how AVs can enhance roundabout performance and boost efficiency, its scope can be further expanded by investigating other aspects, such as safety performance, complex roundabout configurations, and high AVs market share.