As cars trickle by on the way into San Francisco, construction crews are slowly, delicately, painstakingly tearing apart tons of concrete and steel on the Bay Bridge's western span.
Coils of steel wrap around piles of rubble. Rebar juts out of the road deck like gray, broken teeth. A gaping hole eats into the westbound upper deck.
"One of the good things we've seen since we started, is the understanding that the work needs to be done because no one wants to drive over something that's unsafe," said Caltrans spokesman Bart Ney.
Built in 1936, the portion of freeway connecting the western suspension span to San Francisco has been deemed seismically unsafe.
Over the next four years, Caltrans will replace the segment from the bridge to Fifth Street in the heart of the city.
Crews began tearing down the upper deck last weekend and plan to continue the work over the next two weekends -- while letting more than 280,000 motorists continue their daily commutes. Proceed with patience, though -- especially during the weekend of Sept. 30.
"The work you're seeing during the week is basically preparation for the weekends," Ney said. "We're putting in supports to hold up the upper deck while we cut out sections of it."
The work snarled traffic during the past weekend, as lanes, exits and on-ramps were closed to allow crews to work.
More closures are planned this weekend -- though Ney said one key on-ramp, First Street, will remain open -- so traffic is not expected to ease.
"We're hoping it won't be as intense," Ney said.
Traffic jams are expected to return on the weekend of Sept. 30 to Oct. 2 as Caltrans plans to close the entire eastbound lower deck from midnight to 7 a.m. on one of those days.
BART plans to run extra trains to ease the traffic crunch, and Caltrans is urging people to find other ways into and out of San Francisco.
The work officially began in 2003, but the planning has been under way for many years. The West Approach, as the freeway segment is called, is built on the China Basin landfill, a footing more exposed to earthquake damage.
Only one set of columns supports the double-deck freeway -- the exact same configuration of Oakland's Cypress Freeway. Its collapse in the 1989 Loma Prieta earthquake killed 42 people.
Caltrans has rebuilt the Fremont Street off-ramp and recently closed the Harrison Street off-ramp, which will be rebuilt over the next three years.
Once crews finish razing one side of the upper deck next month, commuters will not see major closures again until after the holiday season.
Then work will begin on the other side of the upper deck.
Mike Adamick covers transportation. Reach him at 925-945-4745 or [email protected].
BY THE NUMBERS
Caltrans is retrofitting the "West Approach" that connects the Bay Bridge to the heart of San Francisco.
Cost: $429 million
Years left: 4
Daily commuters: 280,000
Information about lane closures or construction updates online at www.511.org.
BY THE NUMBERS
Sept. 23-26 -- Crews will continue to demolish the "West Approach" but will keep the First Street on-ramp open through the weekend -- a move expected to ease congestion. Still, motorists are advised to use other bridges or take mass transit.
Sept. 30-Oct. 3 -- Crews will wrap up demolition but shut down the eastbound lower deck from midnight to 7 a.m. Motorists are advised to find other routes into and out of the city.
Winter 2005-06 -- Caltrans will begin tearing down another section of the West Approach over several weekends, though details are still being worked out.
Fall 2006 -- Caltrans expects to finish the demolition work, but the bridge will undergo heavy work over several weekends.