| 摘要 |
PROBLEM TO BE SOLVED: To provide a navigation system capable of providing users with appropriate route guidance at all times by resetting guidance points determined by road conditions of intersections and improving reliability and safety by guidance precision. SOLUTION: A guidance development part 44 determines whether intersections present in created route data 45 should be set as guidance points or not and performs the setting processing of guidance points. The guidance development part 44 first sets guidance points at the execution of route computations and performs the setting processing of guidance points again only on intersections which have not been set as guidance points at this time. In the case that nonguided routes in which exit angles from intersections are included in a prescribed direct advance range in exit roads from the intersections are detected at the resetting processing, the intersections are set as guidance points. The presence of route-dedicated lanes on which one can proceed in the direction of a guided route and non-route-dedicated lanes on which one can proceed in the direction of a nonguided route are confirmed. In the case that it is detected that the number of the non-route-dedicated lanes is equal to or exceeds the number of the route-dedicated lanes as a result of number comparison between both lanes, the intersections are also set as guidance points. COPYRIGHT: (C)2006,JPO&NCIPI |
