PURPOSE: To obtain an optimum driving path able to deal with actual congestion status even if no traffic jam information can be obtained in a path guidance device of vehicle which plans the driving path from the current location of driver's own vehicle t a specific driving destination using a map database and then performs path guidance of the driver's own vehicle based on the scheduled driving path.

CONSTITUTION: Heuristics (each information obtained empirically regarding traffic jam) regarding traffic jam input to a driver, etc., from a heuristic input device 28 are stored in a heuristics memory 32. A road condition estimation device 30 estimates the current traffic jam condition from the stored heuristics. A path schedule device 16 plans a driving path considering the estimated traffic jam condition, thus properly understanding the traffic jam condition and then planning the driving path even if the traffic jam information is not obtained yet or cannot be obtained externally.