Control of Traffic Networks Exploiting Vehicle Platooning: State of the Art, Opportunities, and Challenges

Connected and automated vehicles represent a technological breakthrough that can change the concept of mobility, paving the way for a new paradigm of traffic control in which the vehicles themselves can be used to implement traffic control strategies. Indeed, early field experiments have shown that even a small percentage of these vehicles traveling together in the form of platoons acts by limiting the occurrence of traffic instabilities that lead to congestion. In this context, the development of prediction models able to represent the mutual interactions between platoons and vehicular traffic is a key factor. It is then possible to develop model-based control schemes in which the speed of platoons is the adopted control action. The architectures of these control schemes can be of different types, with the control actions defined by a single controller with complete knowledge of the system state, giving rise to centralized control schemes, or with the control problem divided into subproblems, in decentralized control schemes, which are slightly less performant but more computationally efficient. In turn, these control schemes may involve the adoption of a hierarchical architecture in which different levels of control are defined, making the overall control framework more suitable for practical applications.