Route guide information delivery method, route guidance method, information terminal and information delivery center

摘要

Upon receiving a request from a vehicle-mounted device 100, a distribution center 200 executes a recommend route calculation and a guide calculation and transmits recommended route information and the data size of guide information to the vehicle-mounted device 100. The vehicle-mounted device 100 calculates the estimated download time based upon the size of the guide information and displays it. If the driver requests a split download, the vehicle-mounted device 100 outputs a split-download instruction to the distribution center 200. The distribution center 200 transmits to the vehicle-mounted device 100 guide information to be used to guide the vehicle from the start point to the first guidance-requiring intersection. While executing the route guide processing, the vehicle-mounted device 100 downloads the remaining guide information in the background.