Integrated Speed Harmonization and Platooning of Connected Automated Vehicles: Model Development and Large-Scale System Evaluation

In the research presented in the paper, we incorporate two developed controllers—speed harmonization (SH) and cooperative adaptive cruise control—into a single integrated controller. This framework considers the various dynamic and static constraints a vehicle is subject to, including acceleration, velocity, and collision avoidance constraints. The integrated controller was applied to the freeway roadway segments in the downtown Los Angeles network. The results show that both SH and platooning are, by themselves, able to significantly enhance the mobility of the transportation system, with platooning performing best in terms of fuel consumption reduction. SH performed best in terms of travel time and delay reduction. Integrating the two controllers, despite their conflicting mode of operation, produced further reductions in travel time, delay, and stopped delay at the expense of higher fuel consumption levels relative to the platooning only controller. Depending upon the market penetration rate of connected automated vehicles (CAVs), up to a 22%, 43%, 45%, and 12% reductions in vehicle travel time, delay, stopped delay, and fuel consumption were observed. These values are for all the vehicles that traversed the network: CAVs and human-driven vehicles. Since the controllers were activated only on the highway stretches, we can conclude that the enhancement in traffic mobility for a subset of vehicles on a subset of roads can produce significant network-wide impacts on the mobility of all road users. © 2022, The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd.