As Los Angeles' Mayor Antonio Villaraigosa had warned in an apocalyptic press statement on Friday, "The day is upon us." But as traffic seeed to be going smoothly Saturday morning, officials warned that drivers not 'get complacent.' As of midnight, authorities had blocked off a 10-mile stretch of Interstate 405—one of the country's busiest highways—and were met by angry drivers overnight, notably one person who drove in reverse to get off the highway. Most others abandoned their cars. The gridlock was planned months in advance for much-needed construction. Earlier, the mayor addressed the hype about "Carmageddon," and said he expected the whole process "will go very, very smoothly, but it does depend on you." Construction workers are tasked with demolishing a bridge and tearing up some 4,000 tons of concrete on the 10-mile-stretch before reopening the highway in time for early Monday commuters, if all goes according to plan.