Study on an Automatic UAV Cruise Path Planning Method Oriented to Expressway Mainline Control Requirements

To meet real-time control requirements on expressway mainlines, this paper builds an observation–demand model centered on recurrent congestion and short-term congestion fronts and develops a joint planning method for UAV cruise paths and speeds. The method converts long-term priors and short-term forecasts into a priority field and speed constraints. With centerline guidance and a time-metric strategy, it generates trajectories that follow the mainline alignment and support low-speed cruising and loitering in key segments. On this basis, an automated framework comprising five layers, including data, orchestration, planning, execution, and safety, is established to achieve a stable mapping from observation demands to executable trajectories and speed profiles. The study provides actionable paths for proactive observation of recurrent congestion and short-term fronts and lays a practical foundation for integration with mainline control measures.