This study was undertaken to identify methods of unique identification of commercial vehicles at the roadside for slow and high-speed electronic screening purposes. It is a comprehensive look at available and emerging technologies, focusing on the needs of the Federal Highway Administration’s Office of Motor Carrier and Highway Safety (OMCHS) and the States. The study included both a needs assessment and a technology evaluation.A preliminary list of 22 technologies was developed that appeared to have some applicability to the task of roadside identification of commercial vehicles. As the technology evaluation progressed, five of these technologies (optical character recognition, radio frequency identification, barcode, image capture, and voice recognition) emerged as demonstrating the greatest potential for roadside identification of commercial vehicles. These five technologies were evaluated in some detail, and recommendations were developed.