LOS ANGELES - The event many feared would be the "Carmageddon" of epic traffic jams in Los Angeles cruised calmly to a finish yesterday.

Bridge work on Interstate 405 was completed nearly a full day ahead of schedule and officials reopened a 16-kilometre stretch of the busy freeway just after noon Pacific time.

Drivers honked their horns and waved from car windows as traffic started moving in all 10 lanes of the 405 for the first time since being shut down at midnight Friday.

Los Angeles Mayor Antonio Villaraigosa praised contractors for working so quickly and thanked city residents for heeding calls to stay off the roads.

For weeks, authorities warned people that driving as usual on the weekend could back up vehicles from the I-405 to surface streets and other freeways, causing a domino effect that could paralyze much of L-A.

But officials say during the closure there were 65 per cent fewer automobiles on freeways in the L-A metro area, compared with normal weekend traffic.

Local resident Albert Hill says without the traffic it the best weekend ever in L-A.

He says Carmageddon should happen every weekend.

Another closure will be required in about 11 months for more construction.