This paper introduces an intelligent K-band speedometer sensor (KBSS) for ETC (electronic toll collection) system, that is applicable to ad-hoc networks. New and high-precision speedometer sensors have been installed in mobile nodes (vehicles) and on ETC terminals network using K-band Doppler and K-band FMCW (frequency modulated continuous wave) technology, respectively. The ETC network and mobile nodes are organized in an ad hoc manner. The new speedometer sensor is small, inexpensive and low-power device based on the Doppler effects phenomenon to obtain a speed of the vehicle more precisely. The ETC system is capable to locate the position of the vehicles within a long distance from ETC area and without the vehicles even having to slow down during they approach to the ETC gates. The experimental design, data collection and data evaluations are discussed, and the features of the new system have been appraised and compared with a conventional speedometer. The results show that our new speedometer development exhibits a phenomenal performance gains with low cost design, light weight and its performance provides a pragmatic element for emerging ITS infrastructure.