| 摘要 |
PROBLEM TO BE SOLVED: To urge a driver to take a rest during the nighttime for a shorter continuous driving time than during the daytime, by arranging a shorter rest display time, which urges the driver to take a rest more frequently than during the daytime when it judges that the present time belongs to the nighttime. SOLUTION: A navigation system measures the time that a vehicle speed, which is detected by a wheel speed sensor 4 at every specified period of time, is continuously larger than a specified vehicle speed and a rest display part 11 indicates a driver to take a rest in a display 9 when the time reaches a specified time for the rest. In this case, based upon a sunrise/sunset time of each day in a longitude and latitude of local site stored in a sunrise/sunset memory part 12, a date and time at that time read from a clock 7, and a location calculated by a location calculating means 5, it is arranged the time for the rest to be shorter than time at daytime when judging that the present time is at nighttime. As a result, it displays a message to urge a driver to take a rest after a shorter continuous driving time at nighttime than at daytime. |
