The U.S. Department of Transportation's pilot program to open the border to Mexican trucks must be shut down because it is "dangerous and illegal," the Teamsters union argued in the U.S. Court of Appeals for the D.C. Circuit Court this week.

The three-year pilot program was set up to demonstrate the impact of Mexican trucks on U.S. highway safety. The Teamsters allege  the program breaks laws because Mexican trucks do not display proof that they meet federal vehicle safety standards, the drivers do not meet U.S. physical requirements, the trucks do not comply with the National Environmental Policy Act and more.

The case, filed in March, was heard Thursday along with a similar lawsuit by the Owner-Operator Independent Drivers Association against the DOT's Federal Motor Carrier Safety Administration.