OPTIMAL PLANNER SWITCH METHOD FOR THREE POINT TURN OF AUTONOMOUS DRIVING VEHICLES

A three-point-turn is planned and executed in the operation of an autonomous driving vehicle (ADV). A candidate route from a start point and going through an end point is determined, the start point and the end point being in lanes associated with opposite travel directions. The candidate route is categorized into partially overlapping first, second, and third segments. A total cost associated with the candidate route is determined based at least in part on the first and second segments. Whether the total cost is below a threshold cost is determined. In response to a determination that the total cost is below the threshold cost, the three-point-turn is planned based on the candidate route. Further, driving signals are generated based at least in part on the planned three-point-turn to control operations of the ADV.