PURPOSE: To obtain accurately the actual use time of each radio channel by detecting the high level of a receiving part designating the busy state of each radio channel in a multiway radio loop system.

CONSTITUTION: A receiving part 17, which designates the busy state of the radio channel, in a controller MCE11 is in the high level while the channel is busy. When this signal is inputted to an AND circuit 1 in a traffic measuring circuit 18, AND between this signal and a clock is operated, and this clock is inputted to a counter 2. The count value is inputted to a display counter 4 through a driver 3, and a number corresponding to the count value is displayed on the display counter 4. Consequently, the use time of the radio channel including loss is obtained accurately.