A Microsimulation-Based Modelling Approach for Connected and Automated Vehicles on Roundabouts

Connectivity and automation are technologies applied in combination to achieve increases in road safety, traffic efficiency and energy savings. Despite their potential, there are still many open questions regarding how roadway capacity will be affected and what methods should be employed to assess the expected benefits in the transportation domain. In this paper “what-if” scenarios were modelled in Aimsun Next to analyse assumption-based behaviour of automated vehicles operating with a cooperative adaptive cruise control system on roundabouts. The idea behind the study comes from the availability of the capacity adjustment factors for connected and automated vehicles provided by the Highway Capacity Manual for varying market penetration rates. The case study of a single lane roundabout was examined to compare the CAV-adjusted capacity curves and simulated capacities, and to endorse hypothesis on the model parameters of Aimsun Next which mostly affect the CAVs’ ability to increase roundabout’ throughput.