Los Angeles residents appear to have escaped “carmageddon” – the severe traffic jams expected from the closure of a key stretch of highway during one of the city’s busiest weekends.
Interstate 405, the main artery through the city, closed at midnight on Friday, for work expected to take 53 hours.
Workers plan to add more lanes to a 10-mile (16km) section of the freeway.
However, vehicles appeared to be moving freely through the nation’s second-largest city on Saturday.
Transport officials say the highway is being closed to replace the 50-year-old Mulholland Bridge, as part of a $1bn (£600m) project to add additional lanes to a bottlenecked segment of the highway.
The Los Angeles authorities had recruited celebrities with large Twitter followings to warn residents of the closure.
The BBC’s Alastair Leithead at the 405 highway says Carmageddon is in fact all going terribly well as the highway is empty.
With the impending chaos from the closure expected to grind traffic to a halt the authorities had warned motorists to stay off the road. Officials were optimistic that the public had got the message.
“The work is progressing, traffic is co-operating,” said Mike Miles, a district director of the California Department of Transportation.
There is concern, however, that this apparent lack of gridlock might make the public complacent before the route reopens.
“We hope they still listen to what we’re saying and not go out and try to drive through this area, because it is going to be congested if people do that,” Mr Miles said.
During the days leading up to the closure, helicopter taxi rides were being sold for $150 to passengers hoping to get to Los Angeles International Airport during the weekend, and 10-minute flights between Burbank and Los Angeles were being offered by JetBlue for $4 per ticket.
City officials have been issuing bleak traffic warnings to Southern California residents for weeks, reminiscent of flood and wildfire warnings.
Some transport experts have compared the shutdown to other large planned events in the region, like the 1984 summer Olympics, Los Angeles Lakers championship parades and Michael Jackson’s memorial service – events when Los Angeles residents stayed off the roads.
Just like now, “people had advanced notice to get off the roads during the Olympics”, said Genevieve Giuliano, a professor of urban planning and policy at University of Southern California.
“The wildcard is that if the engineers don’t manage to open up the freeway back up after two days,” she added.
The city of Los Angeles asked several celebrities, like Tom Hanks and Ashton Kutcher, to warn Los Angeles residents about carmageddon through the micro-blogging website Twitter.
“This weekend, LA! Avoid Carmageddon, Gas-zilla, 405-enstein, Grid-lock-apalooza! STAY HOME. Eat & shop local,” Hanks wrote.
Facebook also agreed to direct some 6.6 million Los Angeles area residents to the Metropolitan Transportation Authority’s Facebook page for information on avoiding the traffic. – BBC news