The Teamsters Union, joined by Advocates for Highway and Auto Safety and the Truck Safety Coalition, have filed a legal challenge to the Department of Transportation’s (DOT) recent decision to open the border to Mexican trucks.

The lawsuit, filed Tuesday with the U.S. Court of Appeals for the Ninth Circuit, contends that DOT’s final report to Congress violated the Administrative Procedures Act because its conclusion—that Mexico-domiciled carriers operate at a level of safety equal to or greater than U.S. and Canadian carriers—is arbitrary and capricious.

The suit contends the report lacked sufficient data to support such a conclusion.

The DOT announced in January that it would move forward with opening the border to trucks domiciled in Mexico later this year despite an analysis by the DOT Office of the Inspector General (OIG) which acknowledged that it had been unable to develop statistically significant data in the pilot program.

“It is disappointing that the DOT has chosen to ignore the findings of the Inspector General and is moving forward with opening the border to Mexican trucks. The Teamsters Union will continue to fight for highway safety; the safety of our roads cannot be compromised based on this failed program,” said Jim Hoffa, Teamsters General President.

In a letter to the United States Trade Representative (USTR) Michael Froman last week, Hoffa called on the administration to protect highway safety and reopen negotiations over Mexican cross-border trucking as part of the ongoing Trans Pacific Partnership (TPP) talks.

Rep. Peter DeFazio of Oregon, ranking member on the House transportation committee, has suggested he might introduce legislation to reexamine the cross-border trucking program with Mexico.