Vehicular ad hoc networks will enable a variety of applications for safety, traffic efficiency, driver assistance, and infotainment in modern automobile designs. For many of these applications as well as for improving the stability of vehicular adhoc network routing algorithms, it is necessary to know whether a steering wheel rotation has led to a change in the vehicle motion path. The problem is that some steering wheel rotations are temporary and do not lead to a change in the vehicle motion path. In this paper, a GPS-free fuzzy sensor is designed for detecting the change of vehicle motion paths. The implementation results show acceptable precision. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.