| 摘要 |
PROBLEM TO BE SOLVED: To provide a nighttime traveling support navigation device for presenting a guide route capable of heightening safety at the nighttime traveling time by reducing a load of driving by a user at the nighttime traveling time. SOLUTION: Brightness data of each road link are generated and recorded in a map recording medium by utilizing a nighttime satellite picture by DMSP or the like. This navigation device detects brightness of the periphery, operates a guide route corresponding to the nighttime for selecting preferentially a bright road by using the brightness data of the road, when the periphery is dark, and performs guidance along the guide route. If the periphery is predicted to brighten during a travel to the destination, a regular guide route is operated from the prediction spot to the destination. If the periphery is predicted to become dark during a travel to the destination, though the periphery is bright in the beginning of the traveling time and the regular guide route is operated, a guide route corresponding to the nighttime is operated from the prediction spot to the destination. The navigation device predicts a brightness change of the road during the travel from the road brightness data, and informs of the change beforehand. COPYRIGHT: (C)2007,JPO&INPIT |
