20151210 Dense fog makes Los Angeles freeway driving treacherous

Traffic makes it's way through dense fog near downtown Los Angeles, the United States, on Thursday, Dec. 10, 2015. Commuters are being warned of potentially dangerous driving conditions on freeways after heavy fog descended on Southern California. The National Weather Service says a shallow but strong marine inversion has led to a dense fog advisory for Los Angeles Thursday morning. Planes scheduled to land at the Los Angeles International Airport overnight were canceled or delayed because of the fog. (Photo by Ringo Chiu/PHOTOFORMULA.com)