This paper presents the methodology of implementations and performance measurements of our mobile ad-hoc network (MANET) platforms. The work is prompted by the lack of published results concerning the issues associated with the implementation of MANET facilities on actual wireless networks, as opposed to results of simulation experiments. Our MANET is developed based on the settled IEEE 802.11b technology operating in the ad-hoc mode. The opportunity driven multiple access (ODMA), which is developed by IWICS Inc., is implemented on the platform and its performance has been examined through field tests along city streets. Based on the measurement results, ODMA-based MANET facilities are able to provide satisfactory wireless communication services in vehicular environments. The minimum data throughput of 20kBytes/sec could be guaranteed in our testbed.