Abstract: In a navigation apparatus, when a first detour route for detouring around part of an initial route is present and the calculation of a second detour route is instructed, a route search processing unit determines whether the ratio of the distance of the first detour route to the total distance to be traveled when a vehicle returns to the initial route from the current position thereof via the first detour route and travels to a destination exceeds a preset value. If the ratio does not exceed the preset value, the route search processing unit increases cost of at least a link associated with the first detour route, and searches for the second detour route. If the ratio exceeds the preset value, the route search processing unit searches for a new route that links the current position of the vehicle and the destination.

Abstract: Monitoring is performed to determine whether or not the vehicle approaches a first point in a road where the vehicle turns right before a no-left-turn intersection for effectively entering and turning left at the no-left-turn intersection. When it is determined that the vehicle is close to the first point in the road, the direction in which the vehicle should travel from the first point in the road to a second point beyond the no-left-turn intersection is continuously indicated by an arrow in one enlarged view of the intersection.

Abstract: Monitoring is performed to determine whether or not the vehicle approaches a first point in a road where the vehicle turns right before a no-left-turn intersection for effectively entering and turning left at the no-left-turn intersection. When it is determined that the vehicle is close to the first point in the road, the direction in which the vehicle should travel from the first point in the road to a second point beyond the no-left-turn intersection is continuously indicated by an arrow in one enlarged view of the intersection.

Abstract: In a navigation apparatus, when a first detour route for detouring around part of an initial route is present and the calculation of a second detour route is instructed, a route search processing unit determines whether the ratio of the distance of the first detour route to the total distance to be traveled when a vehicle returns to the initial route from the current position thereof via the first detour route and travels to a destination exceeds a preset value. If the ratio does not exceed the preset value, the route search processing unit increases cost of at least a link associated with the first detour route, and searches for the second detour route. If the ratio exceeds the preset value, the route search processing unit searches for a new route that links the current position of the vehicle and the destination.