Combined optimization of connected and automated vehicle distribution and ramp control for weaving scenario

Abstract

The traffic in the weaving region is subject to lane-changing turbulence, which results in a significant impact on traffic safety, reduces traffic efficiency, and creates traffic bottlenecks. To mitigate the negative effect of the weaving, vehicles are distributed in each segment located inside and upstream of the weaving region by a lane-changing advisory using Connected Autonomous Vehicle (CAV) technology, called segment-base lane-changing control (SLDC), and a heuristic optimization algorithm is applied to obtain the proportion of CAVs to be assigned to each segment. Further, to decrease volume variation on the mainline, the ramp metering (RM) control strategy is coordinated and applied to ensure the lane-changing process in the weaving region. Conditions of different traffic demands are analyzed using the cellular automata traffic simulation based on a typical one-sided ramp motorway weaving region. Results indicated that the proposed CAV distribution algorithm and SLDC-RM coordination control strategy could improve traffic efficiency and reduce traffic conflicts. The coordination control is better than SLDC when the occupancy of the weaving region reaches 25 veh/km/ln, also the effects with different proportions of connected vehicles are discussed.