Disclosed is a system and method that offer improved assistance with safe driving using navigation devices, incorporating traffic regulations pertaining to route changes into guidance offered by the navigation devices. The system comprises a traffic regulations data memory (21), which associates, with roadways, data on traffic regulations pertaining to route changes, and stores the data so associated, an onboard vehicle locator (11), which locates the driver's vehicle upon the suggested route, a comparison unit (31), which compares the location of the driver's vehicle, as located by the onboard vehicle locator (11), with the traffic regulations data, and an output unit (40), which outputs, based on the determination made by the comparison unit (31), either information that driving regulations apply upon the road currently being traveled, as part of the suggested route, or that driving regulations apply upon roads ahead of the road currently being traveled, again, as part of the suggested route.