Patent ID: 8306741

Claim:
A navigation method for using routing data created by a remote navigation server for a route guidance operation by an individual navigation system, comprising the following steps of: sending information on a starting point and a destination point to the navigation server from the individual navigation system through a communication network; establishing an optimum route by the navigation server by conducting a route search algorithm on map data retrieved from a map database of the navigation server; determining a road type involved in the optimum route and selecting strategic road segments associated with the optimum route; storing data related to the selected strategic road segments while ignoring data related to road segments other than the strategic road segments; establishing routing data based on the data related to the strategic road segments thereby creating routing data of minimum amount of data; sending the routing data from the navigation server to the individual navigation system through the communication network; and reproducing the optimum route by the individual navigation system based on the routing data and map data retrieved from a map database of the individual navigation system; wherein said step of determining the road type involved in the optimum route and selecting the strategic road segments associated with the optimum route includes a step of detecting a surface road in the optimum route and selecting a road segment that changes a direction of the optimum route such that it destroys assumption that the optimum route is a straightest path as a strategic road segment for the routing data.