LOS ANGELES — A 10-mile stretch of one of the nation's busiest freeways will reopen beginning late Sunday morning because bridge work on the roadway was completed 16 hours ahead of schedule, Los Angeles Mayor Antonio Villaraigosa said.

There have been no major problems since Interstate 405 was shut down at midnight Friday to allow for the partial demolition of a bridge, despite warnings of a "Carmageddon" of traffic jams.

At a Sunday morning news conference, Villaraigosa said workers would start reopening the freeway at about 11:30 a.m. The 405 was expected to be fully reopened as early as midafternoon.

He praised contractors for working so quickly and thanked city residents for heeding calls to stay off the roads. The mayor also gave credit to news outlets for spreading word about the closure, which had been planned to last for 53 hours.

Crews finished demolition work on the bridge at about 7 a.m., toppling two massive pillars.

For weeks, authorities warned people that driving as usual this weekend could trigger what's been hyped as Carmageddon — an event that could back up vehicles from the 405 to surface streets and other freeways, causing a domino effect that could paralyze much of Los Angeles.

But the fears of epic traffic jams dissipated with only light weekend traffic.

"It was just so nice. It took me actually less time to get to work than it would have on a normal weekend," said Jenn Tanaguchi, a hairstylist who has to drive from downtown to her job at a salon in Brentwood. "People were telling me that i would have to leave two hours early, that everything would be blocked out. But there were no problems. It was such a nice ride."

The California Department of Transportation was preparing to reopen the freeway in phases. The off-ramps would open first, then the freeway itself, followed by the on-ramps, the mayor said.

The 405 could be fully reopened as early as 3 p.m., according to Metropolitan Transportation Authority spokesman Dave Sotero.

Demolition work previously was expected to be completed by 2 a.m. Monday, followed by cleanup and reopening of the freeway at 5 a.m., with on-ramps and connectors all reopened by an hour later.

Project contractor Kiewit Infrastructure West faced a $6,000 fine in each direction for every 10 minutes of delay in getting the freeway reopened, according to the city's Metropolitan Transportation Authority. That's a total of $72,000 an hour.

Villaraigosa said Saturday workers have made "great progress" on demolition of the half-century-old Mulholland Bridge. Powerful machines with long booms hammered away at the south side of the span, which was being removed to allow construction of an additional freeway lane. The plan was to leave the north-side lanes standing until the south side is rebuilt. Another closure will be required in the future to demolish the north side.

The project picked up its apocalyptic name when Los Angeles County Supervisor Zev Yaroslavsky said at an early June new conference that "this doesn't need to be a Carmageddon" if people avoided driving.

The drumbeat of warnings about the weekend triggered an instant industry of businesses trying to capitalize. JetBlue offered special flights from Burbank in the San Fernando Valley to Long Beach, with seats for the short hop costing just $4 or $5.

A cycling group saw that as an opportunity for a race. The cyclists started their ride 90 minutes before the flight's departure time to simulate the time that passengers would have to arrive at Burbank. Another member of the group took the flight and all were to meet at a Long Beach park.

Cyclist Stephan Andranian said it took the bikers one hour and 34 minutes to complete the ride from Burbank to Long Beach, largely following the Los Angeles River. Flight passenger Joe Anthony's total travel time including cab ride from Long Beach Airport to the park was just over 2 1/2 hours.

"We want to show that using a bike in LA is not only possible but that it can be faster than other modes of transportation," Andranian said.

Some trespassers have crept on the 405.

Officials report a bicyclist made it onto the road before getting escorted off by police, a man was cited for driving on the roadway, several people were found putting up a large sign, and a man was caught scaling a perimeter fence.

Many mocked the frenzied language surrounding the closure, especially on Twitter, where Hollywood's comedians had at their hometown.

"How's everyone coping with this terrifying apocalyptic nightmare of having to ... oh my god ... stay home with your family?!!!" Bill Maher wrote.

Albert Brooks took a more philosophical in his Tweet: "If we would close the freeways every weekend we would have a great society."