Carmageddon II off to a smooth start

As the sun set and rush hour began to fade on the 405 Freeway on Friday evening, crews gradually shut down ramps and closed lanes of traffic to make room for a small army of construction workers tasked with knocking down the remaining half of the Mulholland Drive bridge this weekend.

The start of Carmageddon II — a 10-mile closure on the nation’s busiest freeway — appeared to be going without a hitch, officials reported early in the evening.

The freeway closure was given the ignominious designation because a similar freeway shutdown a year ago had officials fearing traffic chaos. But that didn’t happen and work crews hope the estimated 53 hours of closure this time will also go smoothly. If they do, the freeway is scheduled to reopen before rush hour Monday morning.

“The reason Carmageddon was a success last summer was because we had the cooperation of the motoring public,” Los Angeles County Supervisor Zev Yaroslavsky said at a Friday evening news conference. “For Carmageddon II to be an equal success, we need to have the cooperation again this weekend.... This is a gargantuan effort.”

Demolishing, and then rebuilding, the bridge is part of a $1-billion freeway improvement project that includes adding a 10-mile northbound carpool lane through the Sepulveda Pass.

Early Saturday, crews will dump 1,200 cubic yards of dirt underneath the 80-foot-tall Mulholland Drive bridge so that falling debris does not damage the freeway roadbed below.

The next steps over the weekend include using jackhammers to ram and punch through the top of the bridge in a process called “slotting,” while other jackhammers will be used to chip away at girders underneath the bridge. Concrete must be removed from both the center and outer spans of the bridge, officials said.

Another step is removing the beams on top of the columns that help support the bridge and then removing the 70-foot concrete and steel pylons, each of which weighs approximately 931,000 pounds.

Then they’ve got to clean up. Crews have also planned a variety of other freeway maintenance work along the way.

Despite the fear of apocalyptic gridlock, the freeways during last year’s Carmageddon were eerily calm and prompted some to say Carmageddon had turned into Carmaheaven. But it’s unclear whether motorists will heed the message to stay out of their cars this weekend.

Katie Cudaback, a 26-year-old accounting manager from West L.A., said that last year she was “totally scared” by the Carmageddon warnings and stayed put for the weekend — keeping to local bars with friends.

But this year Cudaback is a bit more cavalier and was making plans to go out in Hollywood late Friday night.

“We are totally going to make it worse,” she said.

The closure area of the 405 normally carries 250,000 motorists each day on an average weekend. Caltrans District 7 Director Mike Miles said this week that in order for Carmageddon II to be a success, at least two-thirds of those drivers need to stay off the road.

Congestion could also increase dramatically, officials said, if there is a bad accident or lane closures on another major freeway, such as the 101, 5 or 10. K.N. Murthy, of the Los Angeles County Metropolitan Transportation Authority, said the region’s freeway system is not very elastic and can only take on so much additional traffic.

Officials tried to modify their message to motorists from the first Carmageddon, saying “scare tactics” alone wouldn’t work. Instead, they have been encouraging motorists to ditch their cars in favor of public transportation, a bicycle or walking to local destinations.

ari.bloomekatz@latimes.com

Times staff writer Andrew Khouri contributed to this report.