| 摘要 |
PURPOSE: To make an optimum route selectable by displaying a regional road map inclusive of the current position of an own vehicle in a display unit, eliminating those of snarl-up roads inferred from receiving and analyzing the external traffic information, and deducing the shortest route ranging from the current position to each road terminal point on the display screen. CONSTITUTION: A central processing unit 9 gives its indication to a GPS 5 by a display command of an input operating part 1, thereby knowing the current position of its own car. This central processing unit(CPU) 9 reads the road map information of an area inclusive of its own vehicle position from a map information to be registered in an external memory 4, making display control part 3 display this road map. In addition, this CPU 9 gives its indication to a traffic information receiver 8, making it receive traffic information, and it analyzes the securable traffic snarl information, and it eliminates snarl-up roads from a data table. Next, the CPU 9 performs the calculation of the shortest distance from the current position of its own car to each terminal point on a display screen using the Dykstra method. With this constitution, traffic snarl information is added on the road map, through which a time shortest route to the extent of each road terminal point extending to the outside of the display screen is adduceable to people aboard. |
