Towards fair and efficient traffic flow coordination mechanisms for 2+1 roadways
In 2013, 2+1 roadways have become mandatory for newly constructed rural roadways in Germany. The steady trend towards autonomous vehicles and vehicle-to-X (V2X) communication will enable new automated traffic coordination mechanisms. In our research, we study how traffic flow on 2+1 roadways can be improved by using such mechanisms for coordinating the usage of overtaking lanes. Conflicts between vehicles on 2+1 roadways arise due to (1) differing capabilities (e.g. maximum speed), and (2) conflicting preferences of drivers (e.g. desired speed). These conflicts can lead to poor use of resources, and ultimately in time loss both from an individual vehicle and aggregated system perspective. To foster acceptance of coordination mechanisms, it is important to not only consider the system perspective but also to ensure some level of driver satisfaction and fairness, e.g. if vehicles are denied access to the overtaking lane in favour of faster vehicles, this raises questions regarding the acceptance of external coordination. While there is some research studying microscopic optimisation of traffic flows on rural 2+1 roads and intersections, there has been only little research focusing on driver satisfaction and fairness of mechanisms. In this work, we present the results of a pre-study on simulated 2+1 manoeuvres conducted using the Simulation of Urban Mobility (SUMO) suite to estimate optimisation potentials of coordination. Preliminary results indicate potentials to reduce driver dissatisfaction while maintaining fairness. We analyse optimisation potentials and propose a model which combines driver satisfaction and fairness of coordination, aiming at increasing acceptance of autonomous vehicle coordination.