Abstract: An in-vehicle navigator comprises a map memory unit for memorizing road map data consisting of road data comprised of the combination of nodes and links, and background data such as buildings, a location detection unit for detecting a vehicle location, an initialization unit for inputting a destination, and route calculation conditions desired by a vehicle operator, and a route calculation unit for reading road map data containing a current location and the destination from the map memory unit. The route calculation unit also calculates a recommended route, based on the read road map data from the map memory unit and the read route computation conditions from the initialization unit. The navigator further comprises a memory unit for storing the recommended route, and a vehicle guidance unit for detecting an approach to a junction on the recommended route, based on the vehicle location.