PBDR: Pattern-Based Dynamic Routing on Enterprise Service Bus.

Markers each comprising an electromagnetic coil are installed on the surface of a road at a lateral center line of a running lane of the road at predetermined intervals. Provided for each of the markers, a driving signal generating circuit drives the associated marker so that the marker transmits an alternating current magnetic field. Alternating current magnetic field receiving devices each comprising an electromagnetic coil are installed on the front bumper of a vehicle at positions symmetrical with respect to the lateral center line of the vehicle. While the vehicle is running, the alternating current magnetic field receiving devices sequentially receive the alternating current magnetic fields generated by the markers one field after another. A microcomputer receives detection voltages generated by the alternating current magnetic field receiving devices through detection circuits and determines the lateral position of the vehicle from the detection voltages.