A cooperative vehicle platoon is a set of vehicles driving together with low in-vehicle distance enabled by the connected and automated vehicle technology. One of the major benefits of vehicle platooning is energy savings due to air drag reduction. However, as vehicles at different positions in a platoon save differently from the platooning, e.g., the lead vehicles may save little, some drivers or owners of vehicles may not be willing to join or stay in the platoon even if they are advised to do so, yielding behaviorally unstable platoons. The instability further lead to chaos in traffic flow, which is likely to bring unnecessary traffic congestions. As such behavioral side of the problem has been drawn little attention in literature, this study intends to fill this void by focusing on the drivers and owners’ economic consideration of platooning. We envision a freeway system where vehicles are capable of platooning but each platoon has limited size. A novel utility function is proposed to measure a vehicle’s benefit in platooning. Based on that, a mathematical programming model is established to find the optimal platoon formation that specifies which vehicles should be platooned together and their platoon speeds as well as positions to achieve the maximum system benefit. A benefit allocation mechanism, either charges or compensates the vehicles, is then created to incentivize them to form and maintain the desired platoon formation. The model framework is further extended to the setting with an environmental concern, where the proposed mechanism has been shown to benefit not only the vehicles, but also the whole society by bringing greater reductions on traffic emissions.

Xiaotong Sun is a PhD student in the Civil and Environmental Engineering Department.