ROUTE SEARCH SYSTEM, ROUTE SEARCH METHOD, ROUTE SEARCH UNIT, TRAFFIC INFORMATION PROCESSING UNIT, AND COMPUTER PROGRAM

摘要

PROBLEM TO BE SOLVED: To upgrade precision in route search processing while sustaining secrecy of information which a user or road administrator does not want to provide. ! SOLUTION: A route search system includes a route search unit 3 and traffic information processing unit 5. The route search unit performs first route search processing ST3 of searching a route from a departure point to a destination point using plural search requests including the departure point, destination point, and departure time or arrival time. Based on a result of search, the route search unit calculates ST4 passage schedule information representing the number of vehicles scheduled to pass a predetermined point on a road at a time succeeding a current time. The calculated passage schedule information is transmitted ST5 to the traffic information processing unit. The traffic information processing unit produces ST7 risk information, which represents a degree of difficulty which a vehicle has in passing the predetermined point on t