The Bush administration granted authority late on Thursday for long haul Mexican trucks to operate anywhere in the United States, launching a one-year pilot program that some members of Congress, labor and consumer groups assert shortchanges safety.

Transportation Department officials said they had authorized the first Mexican trucking company, Transportes Olympic of the state of Nuevo Leon in northern Mexico, to begin operations. Its trucks could roll within days. Mexico has granted reciprocal authority to Stagecoach Cartage and Distribution of El Paso.

The announcement comes 13 years after Mexico and the United States agreed as part of the North American Free Trade Agreement to permit expanded cross-border trucking to improve shipping efficiency and reduce costs.

Over the past six years, the Bush administration has fought with Congress over safety. The Teamsters union, fearful of job losses among drivers and related personnel, has played an active role in challenging the administration in court and on Capitol Hill.

The administration plans to gradually allow Mexican trucking firms greater access to U.S. highways, topping out at 100 firms and about 500 trucks at the conclusion of the pilot. Currently, Mexican trucks must transfer their goods at areas just inside U.S. border crossings. U.S. trucking firms, until now, have not been allowed to operate in Mexico.

The program will be reevaluated toward the end of 2008 but American officials expressed confidence in the safety protocols that Mexican carriers will have to follow.

John Hill, administrator of the Federal Motor Carrier Safety Administration, told reporters in a conference call that Mexican trucking companies, drivers and vehicles must abide by the same standards as U.S. companies, including truck inspections, licensing and drug and alcohol testing. In some cases the criteria will be stricter, Hill said.

There is a different level of compliance for the Mexican carrier, Hill said. We're committed to following through.

But key Democratic members of Congress are not happy that the program is moving forward at all.

House of Representatives Transportation Committee chairman, Rep. James Oberstar of Minnesota, and the panel's subcommittee chairman on highway safety matters, Rep. Peter DeFazio of Oregon, contended earlier in the day the administration had not met congressional safety mandates for the program and was moving ahead hastily. House legislation passed in July would cut funding for the pilot. The Senate has not acted similarly.

This pilot program should be taken extremely seriously, and treated for what it is: a sea change in surface transportation policy. Yet (the Transportation Department) has expressed little regard for the serious calls of Congress to fully test, evaluate, and understand the impacts of granting Mexico-domiciled motor carriers access to our roads, Oberstar said.

Opponents of the plan say Mexican drivers do not have the same rest rules as U.S. truckers and could cross the border already fatigued. They are also concerned about licensing, insurance and drug testing.

The Teamsters union, which represents about 100,000 long-haul truckers, said the administration has been secretive about the start-up plans and is underprepared.

Transportation officials did not act until the agency's inspector general, Calvin Scovel, had completed a safety review of the pilot program, as required by lawmakers. While the administration felt comfortable with Scovel's findings, Oberstar said the report was inconclusive.

But Hill said regulators fulfilled every congressional requirement on the books and turned up nothing adverse in its safety analysis of the program. We are in compliance.