A federal appeals court last month denied a request by trucking, environmental, consumer and labor organizations looking to stop Mexican trucks from crossing the U.S. border because of high levels of particulate matter and NOx emitted by their diesel engines.
The International Brotherhood of Teamsters was the main plaintiff, along with Public Citizen, Environmental Law Foundation, the California Federation of Labor AFL-CIO, and California Trucking Assn.
The lawsuit was filed just two days before the regulations were to go into effect. The appeals court said the briefing schedule for the case remains in effect.
The regulations are required before President Bush can lift a 1982 moratorium banning Mexican trucks from operating in the U.S.
The suit alleged that DOT didn't conduct a thorough analysis of the environmental impact of Mexican trucks when making its recommendations earlier this year. The suit claimed Mexican trucks don't have to meet the same emission standards as U.S.-based vehicles.
