Comparative research into roundabout performance for highly automated vehicles

Introduction . With the rapid development of highly automated vehicles (HAVs), the issue of adapting existing road infrastructure to ensure their uninterrupted and safe operation is becoming increasingly relevant. Roundabouts, due to their ability to reduce the number of potential conflict points and improve overall safety compared to conventional intersections, are considered as a means of enhancing road safety. However, they are not significantly effective in terms of increasing capacity and optimizing traffic flow. Materials and Methods . This study is dedicated to a comparative assessment of the efficiency of HAVs on roundabouts. The paper examines the advantages of HAVs, their impact on traffic flow, and analyzes simulation results at the micro (or meso-) level using SUMO software. It demonstrates the influence of different roundabout configurations on the movement of both manually driven and autonomous vehicles within traffic streams. Results . Simulation results have shown that the use of roundabouts for pure HAV traffic flow is inefficient. Although roundabouts are promoted as a way to improve road safety by replacing conflict points with weaving zones, the algorithmic navigation of HAVs on intersections inherently prevents hazardous situations, as conflicts are resolved in advance. The most critical factor for increasing the throughput of HAVs at intersections is the width of the roadway. At present, no precise quantitative indicators to demonstrate the road width impact on HAVs capacity have been established, however, it is possible to highlight such important aspects as the possibility of uniform traffic flow, typical for piloted vehicles, and, hence, higher volume of HAV traffic flow. Discussion and Conclusion . The findings of this study can serve as a foundation for optimizing existing transportation infrastructure and developing recommendations for designing intersections adapted to autonomous traffic conditions. They also provide a basis for further research aimed at increasing the capacity of various types of road intersections under high levels of traffic automation.