Optimal route planning with restrictions for car navigation systems

The optimal route search in car navigation systems is often considered to be a route search from the origin to destination. Many algorithms have been proposed to search for the optimal route from the origin to destination. However, in real situations several restrictions may need to be considered in the route search like some intersections must be included in the route while some should be excluded. The conventional optimal route search methods cannot consider such restrictions in the route search. In this paper, we propose a method to find the optimal route considering such restrictions, focusing on the restriction that some intermediate destinations must be visited before reaching the final destination. The proposed method is divided into three steps. In the first step, the optimal traveling times among the origin, intermediate destinations and final destination are calculated. In the second step, the optimal order of visiting intermediate destinations is optimized using RasID-D, a random search method for discrete optimization problems. Finally, in the third step, the optimal route from the origin to destination via intermediate destinations is determined. The paper also discusses the heuristic initialization to increase the efficiency of the optimal search. The proposed method was evaluated using a grid network with randomly generated intermediate intersections. Simulation results showed that the proposed method is more efficient than the genetic algorithm for optimizing the visiting order.