Coordinating traffic at urban intersections is crucial in traffic control systems, and the advent of connected vehicles enables to consider more flexible paths and potentially improve efficiency.

The authors of this paper consider the area of a signal-free intersection as a bounded free space, where connected vehicles under automated driving (CVAD) are allowed to take free paths under the condition that the trajectories do not collide.

The authors’ model is as an extension of a nonlinear model predictive contouring control (NMPCC) which has the goal of both generating collision-free trajectories for the vehicles and optimizing the progress of the vehicles along their trajectories. The model involves constraints to avoid collisions and violations of intersection boundaries.

The model results in a Nonlinear Program (NLP). Artelys Knitro with the multistart option is exploited to solve it. Results show that this model allows shorter travel time with respect to a conventional approach, due to improved space utilization. The performance of the solution shows that even a real-time operation is feasible in the studied scenario.