The Teamsters Union has filed a legal challenge to the U.S. Department of Transportation’s (DOT) recent decision to permit Mexican long-haul motor carriers to operate in the U.S. beyond the designated border zone. Specifically, the union is targeting a report published by DOT following the October 2014 conclusion of the two-year Mexico Cross-Border Trucking Pilot Program, which determined that Mexican motor carriers operate just as safely as their U.S. and Canadian counterparts within the U.S. and paved the way for a more permanent long-haul trucking program.

The Teamsters, along with the Advocates for Highway and Auto Safety and the Truck Safety Coalition, allege the report violated the Administrative Procedure Act “because its conclusion … is arbitrary and capricious in light of the admitted lack of significant data from a pilot program Congress required DOT to conduct.”

The lawsuit, filed in the 9th Circuit Court of Appeals in San Francisco, charges that the pilot program “failed to test the safety of long-haul operations originating in Mexico and traveling throughout the U.S. beyond the commercial zones where Mexican trucks are already permitted to travel.”

In a letter to U.S. Trade Representative Michael Froman last week, Teamster’s General President James Hoffa called on the Obama Administration “to protect highway safety and reopen negotiations over Mexican cross-border trucking as part of the ongoing Trans Pacific Partnership (TPP) talks.”

According to the DOT, the move to allow Mexican truckers on all U.S. highways “marks a significant milestone in implementation of the North American Free Trade Agreement.” The policy change, the agency said in a statement, “is expected to result in the permanent termination of more than $2 billion in annual retaliatory tariffs on U.S. goods,” and Mexican truckers will be held to the same standards as U.S. and Canadian long-haul operators.

Companies from Mexico that apply for long-haul operating authority will be required to pass a Pre-Authorization Safety Audit to confirm they have adequate safety management programs in place, including systems for monitoring hours-of-service and to conduct drug testing using an HHS-certified lab, the DOT said. “Additionally, all drivers must possess a valid U.S. Commercial Driver’s License or a Mexican Licencia Federal de Conductor, and must meet the agency’s English language proficiency requirements.”

Like Canadian companies that are granted U.S. operating authority, carriers and drivers from Mexico are required to comply with all laws and regulations, including regular border and random roadside inspections. Once the motor carrier is approved, the DOT said, their vehicles will be required to undergo a 37-point North American Standard Level 1 inspection every 90 days for at least four years.