A Reliable Wireless Protocol for Highway and Metered-Ramp CAV Collaborative Merging with Constant-Time-Headway Safety Guarantee

To realize the grand vision of automated driving in smart vehicle cyber-physical systems (CPS), one important task is to support the merging of connected automated vehicles (CAVs) from a metered-ramp to highway. Certain safety rules must be guaranteed. However, this demand is complicated by the inherently unreliable wireless communications. In this article, we focus on the well adopted constant-time-headway (CTH) safety rule. We propose a highway and metered-ramp CAV collaborative merging protocol, and formally prove its guarantee of the CTH safety and liveness under arbitrary wireless data packet losses. These theoretical claims are further validated by our simulations. Furthermore, the simulation results also show significant improvements in the merging efficiency over other solution alternatives. Particularly, the merging success rates are more than 99% better in 11 out of 18 comparison pairs, and 0% (i.e., tied) ∼71% better in the remaining 7 comparison pairs.