On the Cooperative Automatic Lane Change: Speed Synchronization and Automatic ``Courtesy''

The recent ability of some vehicles to handle autonomously the lane change maneuvers, and the progressive equipment of roads and vehicles with ITS-G5 units motivate this paper to consider the case of road narrowing that requires a lane change because one lane is occupied by road works for maintenance, incidents and so on. This paper extends the approaches of cooperative speed synchronization at intersections. Because of the complexity of the overall system, it considers each automatic lane change as a mobile (unfixed) intersection in which vehicles synchronize their velocities. The wireless communication allows each vehicle to increase its field of view to negotiate its merging with the other equipped vehicles. Hence, the proposed approach introduces a kind of automatic ``courtesy'' between equipped vehicles. The paper defines the intersection point between each pair of vehicles and the suited protocol to safely reach the new lane. The protocol can be handled by the new work item (NWI) that has been created at ETSI to realize platooning and cooperative adaptive cruise control. Besides enhancing safety, the simulation results show that the main advantage of the approach is the energy saving by smoothing the traffic.