"Supreme Court justices [Tuesday] appeared receptive to the trucking industry's call to strike down a Port of Los Angeles program designed to clean up some of the country's most diesel-polluted air."

"The port, the largest in the country, launched its Clean Truck Program in 2008 and has cut diesel particulate emissions from trucks by more than 50 percent.

But trucking associations argue that the port's program, which requires trucks to meet certain conditions before obtaining access to the port, is prohibited by a 1994 federal law that deregulated their industry.

Conservative justices today embraced that sentiment and said the exemption to that law sought by the port -- that it is a 'market participant' -- doesn't exist."

Jeremy P. Jacobs reports for Greenwire April 16, 2013. [2]