Automated Vehicles and Infrastructure Design

Urban road traffic will increase in the upcoming years due to urbanization and it is expected that this trend will continue. Automated Vehicles (AVs), as one of the solutions, are expected to contribution to improve the traffic flow efficiency, traffic safety, and the environment. The implementation of AVs on highway is expected to be the most promising first step in the near future. One of the concerns regarding the implementation of AVs on highway is the mixed traffic situation, where automated vehicles and manually driven vehicles (MVs) drive simultaneously. Different studies suggest a dedicated lane as a solution to overcome these concerns. However, evidence-based research on the implications of dedicated lanes is still missing.

A driving simulator experiment to observe behavioral adaptation of drivers of manual vehicles exposed to different road design scenarios of a dedicated lane have been conducted. The results of this experiment are incorporated in VISSIM traffic flow models to test the influence of such a dedicated lane on the traffic flow. It appeared that drivers decrease their THW when they are driving directly next to a platoon of AVs while this was not observed when there was a guardrail separating them. With regard to a dedicated lane with a continuous access, the traffic flow is improved once penetration rates of AVs of 15- to 20% have been reached. For dedicated lanes with a limited access and thus specified entry- and exit ramps, the traffic flow is only improved for penetration rates of 30- to 35%.

The observed decreased THW of drivers of manually driven vehicles might threaten the safety when there is no physical separation between them and the dedicated lane. Therefore, safety issues should be extensively investigated in further research. This thesis set the first steps in investigating the implications of a dedicated lane for AVs on the highway in the Netherlands, but for actual implementation more research is needed.