California Air Resources field representative Valente Armenta (L) and Jose Andujar look into the engine of a truck as they work a checkpoint set up to inspect heavy-duty trucks traveling near the ... more 
California Air Resources field representative Valente Armenta (L) and Jose Andujar look into the engine of a truck as they work a checkpoint set up to inspect heavy-duty trucks traveling near the Mexican-U.S. border in Otay Mesa, California September 10, 2013. California Highway Patrol and the Air Resources Board were inspecting trucks for compliance to California's air pollution laws. REUTERS/Mike Blake (UNITED STATES - Tags: ENVIRONMENT) less 
1 / 6
Reuters | Photo By MIKE BLAKE / REUTERS
Wed, Sep 11, 2013 3:33 AM EDT