Internal boundary control in lane-free automated vehicle traffic: Comparison of approaches via microscopic simulation

The recently introduced TrafficFluid concept proposes that automated vehicles drive lane-free, thus enabling capacity sharing between the two opposite road directions via real-time Internal Boundary Control (IBC). This novel traffic control measure was demonstrated, using macroscopic traffic flow models, to deliver unprecedented improvements of traffic flow efficiency. The present study completes and validates the IBC concept in a much more realistic way via microscopic simulation and active internal boundary moving, using the SUMO-based TrafficFluid-Sim simulation tool. To effectuate IBC, a Linear Quadratic Regulator (LQR), which is a feedback control scheme, is employed. In addition, to enhance the performance of the LQR controller, a feedforward term, accounting for external disturbances, i.e. entering flow and on-ramp flows, is also designed, leading to an augmented LQR-FF control scheme. The LQR and LQR-FF controllers are tested and compared in the created realistic environment, demonstrating how IBC may operate in practice to combat traffic congestion on highways.