The operations of tractor-trailers, mixed with other vehicles on US interstates, has resulted in a number of major tractor-trailer overturn events which often cause traffic to stop for hours along a major traffic corridor because the wreckage physically blocks the corridor. In some cases, the blockage remains for a day or more if toxic substances are being carried by the tractor-trailer. Mixed vehicle use of the interstates coupled with the fact that some tractor-trailers with high center of gravity loads are driven too fast ensure that the overturn events experienced to date will continue. In a previous SPIE paper, the Georgia Tech Research Institute researchers demonstrated that an X-band radar (10.5 GHz) could detect the oscillation frequency of tractor-trailer trucks within 1,000 feet of the radar. This radar was used to control a vibration damper on a bridge to provide longer bridge life. Previous studies conducted by GTRI show that tractor-trailer trucks reflect several orders of magnitude more energy than passenger vehicles, vans and other smaller trucks. In many cases, the large tractor-trailer truck radar signature alone could be used to identify the trucks from the other traffic. However, since non-ranging homodyne radar was being used, it was not known if smaller radar cross section targets that were closer to the radar than the tractor-trailer trucks would have a larger radar signature. This paper examines the issues associated with identifying tractor-trailer truck radar signatures from the radar signatures of other vehicles within the antenna beam of a non-ranging homodyne radar.