  This paper proposes collision-free optimal trajectory planning for autonomous
vehicles in highway traffic, where vehicles need to deal with the interaction
among each other. To address this issue, a novel optimal control framework is
suggested, which couples the trajectory of surrounding vehicles with collision
avoidance constraints. Additionally, we describe a trajectory optimization
technique under state constraints, utilizing a planner based on Pontryagin's
Minimum Principle, capable of numerically solving collision avoidance scenarios
with surrounding vehicles. Simulation results demonstrate the effectiveness of
the proposed approach regarding interaction-based motion planning for different
scenarios.
