Almost one-third of the heavy trucks on U.S. roads now use the most stringent emission-control systems, which radically reduce their emissions of nitrogen oxides, soot, and other pollutants. Commercial trucks log much higher annual mileage than passenger cars, especially the semi tractors that haul long-distance freight across the country. That... Several states wants far cleaner diesel trucks; EPA to start rulemaking?
Almost one-third of the heavy trucks on U.S. roads now use the most stringent emission-control systems, which radically reduce their emissions of nitrogen oxides, soot, and other pollutants. Commercial trucks log much higher annual mileage than passenger cars, especially the semi tractors that haul long-distance freight across the country. That...