Because of a law passed last year, Mexican truckers who travel beyond designated U.S. commercial zones will be breaking the law.

Mexican trucks have been barred from hauling in the U.S. since 1995 when President Clinton blocked a provision of the North American Free Trade Agreement that would have given U.S. and Mexican truckers access to each other's border states. Under NAFTA, both countries would be fully open to U.S. and Mexican truckers this year. But the President, citing safety concerns, has delayed enactment of those provisions. Mexico responded by banning most U.S. trucks.
Yet Mexican truckers contine to serve U.S. customers through an obscure 1930s law that let them operate here as long as they have a lease agreement with a U.S. carrier.
After outcries from U.S. truckers who were being undercut by their Mexican competitors, Congress banned the lease arrangements as part of the Motor Carrier Safety Improvement Act. The prohibition was effective January 1 but federal and state agencies gave Mexican carriers and extra three months to comply. Starting Tuesday, Mexican truckers who drive beyond the border zones risk state fines of $2,700, federal fines of $10,000 and, for repeat offenders, seizure of their trucks, trailers and cargo. The only exception is truckers carrying goods produced by the company that owns the truck.
Mexican officials have protested, saying the ban is a violation of the free trade agreement. The matter is scheduled for consideration by a NAFTA arbitration panel in June.