| 摘要 |
PROBLEM TO BE SOLVED: To guide a mobile vehicle for changing lane accurately by determining the traveling lane of the mobile vehicle based on the positional data of the mobile vehicle and the lane data of road stored in a memory means. SOLUTION: When an automobile approaches a recommended course or a crossroads, a CPU 10 determines the advancing direction at the crossroads based on a recommended course. When the determined advancing direction is not straight, the CPU 10 judges of whether the automobile is currently traveling on a road of two lanes or more based on the road information stored in a CD-ROM at a CD block 5. When the automobile is traveling on a road of two lanes or more, a decision is made whether the currently traveling lane is led to a straight advance lane, a right turn lane or a left turn lane at the crossroads. When a decision is made that the recommended advancing direction at the crossroads registered in an RAM 9 is different from the currently traveling lane, the CPU 10 guides the advancing direction at the crossroads according to the recommended course and then guides the changing of lane. |
