Patent ID: 7617046

Claim:
A navigation apparatus for storing and using information about a detour route that diverges from a branch point on a guidance route and merges into the guidance route at a junction point, comprising: a memory that: stores path information for a path each time the path is traveled, the path being a segment of the guidance route from the branch point to the junction point, the path information including a first required time to travel the path, a traffic condition of the path at the time the path is traveled, and a traffic condition of the detour route at the time the path is traveled; and stores detour route information for the detour route each time the detour route is traveled, the detour route information including a second required time to travel the detour route, a traffic condition of the path at the time the detour route is traveled, and a traffic condition of the detour route at the time the detour route is traveled; and; a controller that: receives current traffic conditions from an external system; reads out, when arriving at the branch point, path information having a same or similar stored traffic condition as a current path traffic condition and detour route information having a same or similar stored traffic condition as a current detour route traffic condition; determines a difference between the first required time for traveling along the path and the second required time for traveling along the detour route; and outputs guidance information based on the determined difference.