Traffic safety of connected and autonomous vehicles at ramp junctions – a simulation-based analysis

Literature and designers expect that CAVs will perform more homogenous driving behavior at ramp junctions. This study employs a simulation-based analysis to investigate driving dynamics at motorway-ramp junctions during the introduction of CAVs. Six different scenarios of CAV introduction featuring varying levels of automation and penetration rates are simulated within the Aimsun microsimulation platform. Conflicts at merge/diverge junction areas are described and spatially analysed in terms of factors such as section volume, speed, number of lanes, area type, and ramp configurations. The results indicate that scenarios characterised by high CAV penetration rates will experience a significant reduction in the impact of the considered factors on traffic safety (e.g. access, ramp, and area types). This research serves as a valuable reference for policymakers and stakeholders, shedding light on the design and operational parameters that influence traffic safety in motorway access areas during the introduction of CAVs.