Patent ID: 7809503

Claim:
A navigation apparatus comprising: a guided vehicle position determining portion that determines the position of a guided vehicle; and a controller that: searches for a recommended route to a destination point; determines a problem condition identified position that will be subject to problem condition identification based on a relation to an initial course change point on the recommended route ahead of the guided vehicle's position; at the problem condition identified position, identifies the presence or absence of a problem condition that makes it likely that the guided vehicle will deviate from the recommended route, based on peripheral carrier information, which is information related to carriers that are traveling in the vicinity of the guided vehicle; and if a problem condition is present, sets a starting point at a position where the guided vehicle is anticipated to reach after deviating from the recommended route, and searches for a new recommended route from the starting point to the destination point, wherein a distance from the initial course change point on the recommended route to the problem condition identified position is variable.