The International Brotherhood of Teamsters was the main plainiff, along with Public Citizen, the Environmental Law Foundation, the California Federation of Labor AFL-CIO and the California Trucking Assn.
The lawsuit was filed just two days before the regulations were set to go into effect. The appeals court said the briefing schedule for the case remains in effect.
The regulations, outlining safety and operational requirements, are required before U.S. President George W. Bush can lift a 1982 moratorium that bans Mexican trucks from the U.S.
The suit alleges DOT didn't conduct a thorough analysis of the environmental impacts of the Mexican trucks when making its recommendations earlier this year. Mexican trucks don't have to meet the same emission standards as American vehicles, the suit said.
