23. Joint optimization of all vehicle trajectories at a highway weaving area in lane-free traffic

The video corresponds to the results presented in a Conference paper, titled "Joint optimization of all vehicle trajectories at a highway weaving area in lane-free traffic", presented to IEEE ITSC 2026. A centralized path-planning approach is applied to all connected and automated vehicles (CAVs) navigating a lane-free highway weaving section. The vehicle trajectories are obtained by solving a joint optimal control problem for all vehicles on the road, as detailed in the paper. We present a scenario involving 200 vehicles with diverse characteristics (dimensions, desired speeds, etc.) specified in paper. 70 vehicles merge into the mainstream from the on-ramp, 60 vehicles diverge to the off-ramp, and 70 vehicles travel through the weaving section on the mainstream. As usual for weaving sections, the on-ramp’s acceleration lane coincides with the off-ramp’s deceleration lane, and the distance between the end of the on-ramp and the start of the off-ramp is 610 m. The width of the mainstream upstream and downstream of the weaving area is 13 m, while the width of the acceleration and deceleration lane is 5 m. The green vehicles are on-ramp vehicles, red ones are off-ramp vehicles, and the blue vehicles represent the mainstream vehicles. The solid white curved line represents the left boundary of the weaving section, while the white dashed straight line denotes the right boundary of the mainstream. Weaving sections are particularly challenging traffic areas, as many vehicles with different origin-destinations must cross paths. At high traffic flows, these interactions create complex driving situations that result in speed reductions and a decrease in roadway capacity. The video is shown at 1x real-time speed. Joint trajectory planning enables vehicles to cooperatively plan their maneuvers, as the optimization is performed for all vehicles simultaneously and over the entire time horizon. At the end of the scenario, the vehicles have safely passed through the weaving area. In this video, the camera is stationary and captures the movement of vehicles as they pass the weaving area. Specifically, some vehicles drive through the weaving area, others merge onto the mainstream from the on-ramp and yet others exit the mainstream via the off-ramp safely (no collisions), conveniently (moderate accelerations) and with average speed only slightly lower than the average desired speed.