PURPOSE: To prevent radio interference due to simultaneous calling from plural taxies by giving the priority of transmission of a dynamic data of the taxies to a base station depending on a traffic crowding district and a traffic slacking district based on the waiting time of an empty taxi.

CONSTITUTION: In collecting a dynamic data of the taxies with a polling signal from the base station, a timer is operated by a position group signal from the sign post of a prescribed district and a signal showing an empty car on a taxi meter to count the waiting time of the district. In case of the traffic crowding district or traffic crowding time zone, the priority is lowered alternately sequentially to the longer waiting time and the shorter waiting time and set such as first priority of response to the base station for 3∼3.5min waiting time as a reference time, 2nd priority for 3.5∼4.5 time zone, and 3rd priority for 2.5∼3min. In case of the slacking area or slacking time zone, the waiting time of 15min is used as the 1st priority, and the pirority is lowered sequentially toward the shorter waiting time.