The coalition, which filed a similar suit in April, includes Public Citizen, the Environmental Law Foundation, the International Brotherhood of Teamsters, the California Federation of Labor AFL-CIO and the California Trucking Assn.
As it also claimed in April, the group says the federal government did not adequately review the impact the trucks would have on U.S. air quality. The 9th U.S. Circuit Court of Appeals gave the government a Wednesday deadline to respond.
The Dept. of Transportation said it would not comment on the suit because it is under review.
Last week, President Bush opened U.S. highways to Mexican trucks beyond the 20-mile commercial border zones where Mexican rigs currently transfer their cargo to U.S. trucks that carry the loads to points within the United States.