Available bandwidth, along with latency and packet loss ratio, is an essential metric for efficient operation of overlay network applications. However, the measurement of available bandwidth requires a larger amount of probe traffic than other metrics. Furthermore, measurement conflict between paths with overlapping routes can seriously degrade measurement accuracy and cause a non-negligible increase in the network load. In this paper, we propose a distributed method for measuring available bandwidth in overlay networks that can reduce measurement conflicts while maintaining high measurement accuracy at low cost. The main idea is that neighboring overlay nodes exchange route information to detect overlapping paths and share the measurement results of overlapping paths to configure parameter settings for measuring available bandwidth. Simulation results indicate that the relative errors from measurements using the proposed method are only approximately 65% those of an existing method.