Calif. proposes air rule for trucks

California officials have released a toughest-in-the-nation plan to cut emissions of air pollutants from the roughly 1 million heavy-duty diesel trucks that travel California's roads.

The rules proposed by the state Air Resources Board on Friday would require older big rigs to be fitted with particle-trapping exhaust filters by 2014 and low-emission engines by 2020. In addition, aerodynamic fairings and low-rolling-resistance tires would be required on long-haul trucks to improve fuel efficiency.

The changes would help California meet air-quality standards set by federal regulators, as well as the state's own greenhouse-gas targets.

Read the full story at