As early as Feb. 24, the U.S. Supreme Court could begin to issue decisions on four environmental cases, including one that would make it easier for Mexican trucks to operate on U.S. highways, according to Gannett News Service.

The Mexican truck case – Department of Transportation vs. Public Citizen – involves the North American Free Trade Agreement, which lifted trade barriers between the United States and Mexico starting in 1994.

In 2002, President Bush lifted a prohibition on Mexican trucks traveling in the United States after the Transportation Department wrote safety rules for the Mexican fleet.

Public Citizen, an advocacy group founded by Ralph Nader, has sued the Transportation Department. It says the department failed to conduct a thorough environmental analysis of its rules – including the impact of tens of thousands of Mexican trucks on U.S. highways.

The government says the Mexican truck traffic would be the result of a presidential action – Bush's lifting of the ban – and therefore isn't subject to environmental review

Meanwhile, by the time the court term ends in June, justices will have ruled on eight cases bearing on the environment – the most heard in one term in a decade.