WASHINGTON (AP) -- The Supreme Court has overturned part of the anti-smog program at the Port of Los Angeles.
The port tried to restrict the types of trucks that can haul goods in and out of its terminals. But justices voted unanimously Thursday to strike down part of the port's Clean Trucks Program.
The port wanted companies to replace thousands of aging big rigs with newer, cleaner-burning models to reduce diesel emissions.
The high court says federal law pre-empts the port's decision to make companies develop an off-street parking plan and display designated signs on their vehicles.
But the court did not say whether the port could use other parts of the agreement with truckers to punish violations of other provisions it left intact.