Cooperative Strategy of Connected and Autonomous Vehicles at a Freeway Merging Area

The Cooperative Adaptive Cruise Control (CACC) operation strategy can not only increase the probability of individual CACC vehicles joining platoons, but also has the potential to improve roadway capacity and mitigate traffic congestion thanks to the short following gap enabled by vehicle-to-vehicle (V2V) communication. However, CACC operation may disturb the normal merging behavior of on-ramp vehicles when the market penetration rate is not high enough. In this paper, three cooperative strategies are proposed, which are tightening the gap between CACC vehicles in the same platoon, splitting a long CACC platoon into several shorter platoons, and setting a dedicated CACC lane. The effectiveness of each strategy is verified through an integrated simulation platform. Results under various CACC market penetration demonstrated that strategies can effectively improve the capacity while reducing the queue length in the freeway merging area.