For the same period, these vehicles made an estimated 4.5 million crossings of the border. During 2000, federal and state inspectors performed approximately 97,000 inspections of vehicles engaged in cross-border operations. Approximately 8,500 companies currently have such authority. The Motor Carrier Safety Act of 1984 confined most Mexican motor carriers to these border commercial zones as defined by the former Interstate Commerce Commission. In fact, its width varies, but in only two commercial zones does it extend further than 25 miles into the United States.
Commercial zones exist throughout the United States.
They originally were established for economic regulation. All commercial vehicles operating in the United States, foreign and domestic, must comply with Federal Motor Carrier Safety Regulations and all other requirements applicable to U.S. carriers.