Click photo to enlarge
Traffic flows past the infamous Bay Bridge S-curve where a big rig packed with Asian pears drove off the span at 3:30 am Monday Nov. 9, 2009. A mattress from the truck remained wedged on the outside of the K-rail. (Karl Mondon/Staff)

Caltrans says it's too early to know when the Bay Bridge will be closed again to make more permanent repairs on a cracked metal beam.

Though the repair is expected to be undertaken this year or in early 2010, a date can't be set until the highway agency determines how it will fortify a cracked eyebar, Caltrans spokesman Bart Ney said Wednesday, downplaying media reports that the closure could occur before Christmas.

"At this point, it's only a slight possibility," Ney said. "I would bet this would happen after New Year's, but I cannot confirm until a design is determined."

Meanwhile, Caltrans expects in about two weeks to install radar-equipped flashing signs telling motorists their speed while traveling the accident-prone S-curve on the Bay Bridge, Ney said. The radar signs are one of several measures aimed at getting motorists to slow down after a trucker plunged off the curve to his death Monday.

The S-curve is just east of Yerba Buena Island. A little further to the east on the bridge is the cantilever section where the eyebar crack was discovered over Labor Day weekend during a scheduled closure.

Repair crews installed a giant metal brace on the cracked eyebar, but pieces of that brace fell onto the freeway Oct. 27, triggering a six-day closure so Caltrans could reinforce the brace to reduce vibration.

The latest fix is temporary because it requires heavy maintenance and inspections that make daily lane closures on the bridge necessary, Caltrans officials say.

Caltrans officials are looking at a variety of repair options, including replacing the eyebar or installing more metal reinforcements to protect it. "The designers are just sitting down with the possibilities," Ney said.

A decision on how to make repairs probably will be made in about a month. Adding to the uncertainty of the closure date is the fact that Caltrans hasn't determined what materials will need to be ordered or manufactured for the repair, he said.

The decision on the repair date also will be influenced by the best time to minimize the widespread commute disruption caused by closing the busy bridge. Some 280,000 vehicles a day cross the span between Oakland and San Francisco.

"We want to get the work done sooner than later, but we have to think about the impact on Bay Area traffic," Ney said.

Caltrans picked Labor Day weekend — a time of low traffic volume — for planned closures of the Bay Bridge in 2007 and this year.

Meanwhile, Caltrans continues looking into options to alert motorists to the 40-mph speed limit on the S-curve.

Caltrans is looking into the possibility of installing rumble strips across all five bridge lanes to alert motorists they are about to enter the S-curve. However, Ney added, officials are concerned the rumble strip might be a hazard to motorcyclists.

Reach Denis Cuff at 925-943-8267. Read the Capricious Commuter blog at www.ibabuzz.com/transportation.