The Bay Bridge has been closed three times over Labor Day weekend since 2006, and it's never caused real traffic nightmares.
This year? Think again.
The shutdown of the bridge, part of a $6.4 billion project to replace the eastern span, begins at 8 p.m. Wednesday and could last until 5 a.m. Tuesday. That's two days longer than in past years -- and includes two weekdays, Thursday and Friday, when thousands of drivers may be heading to work or preparing to get out of town for the last weekend of summer.
The AAA predicts a 6 percent increase in the number of cars on state roads this weekend from a year ago. That's more than 3.9 million Californians traveling 50 miles or more from their homes.
"Taking the Bay Bridge out of the equation is mind-boggling," said longtime Bay Area traffic reporter Joe McConnell. "It could be chaos those two afternoons."
San Francisco officials recommend adding one to two hours to driving trips to the city while the bridge is closed. The big attraction will be the America's Cup races on San Francisco Bay. A likely headache will be the Critical Mass biking event that begins at 5:30 p.m. Friday at Justin Herman Plaza.
On the other side of the bay, the Cal football team kicks off the season Saturday night, and the playoff-chasing Oakland Athletics are home Friday through Monday.
Still insisting on going into or out of San Francisco? Think BART, BART, BART if you don't mind standing. Trains will run all night, and extra cars will be added.
"I'm taking BART on Thursday into work," said Thomas Senner, who normally drives across the Bay Bridge from the Berkeley area. "But I figure I need to count on an extra hour to get to work."
During the last Labor Day weekend closure four years ago, BART ridership jumped 30 percent, with an extra 230,000 passengers, compared to the same period the year before.
But many others still will drive, and the options are not good. Traffic on the San Mateo Bridge has been more congested for months, and Highway 101 along the Peninsula is a constant challenge. Interstate 880 is not called the Nasty Nimitz without reason.
Some motorists may take the Golden Gate and Richmond-San Rafael bridges. While the conversion to all-electronic tolling has sped up the Golden Gate Bridge drive, road work has slowed the commute on Interstate 580 east of the Richmond Bridge.
More ferries will criss-cross the bay, and AC Transit will reroute buses that normally cross the bridge to BART stations in the East Bay.
The last time the bridge closed was in the middle of the recession in 2009, and this year could be much worse, said Jamie Holter of the transportation tracking agency INRIX. In 2009, the 280,000-plus everyday users found other ways to move between the East Bay and San Francisco, and the closings ended sooner than scheduled.
Doom-and-gloom predictions were not met, thankfully.
But this year the experts are nervous.
"It will be very busy Thursday afternoon from 2 to 7 as people rush to get out of town via the San Rafael Bridge and the Dumbarton Bridge," Holter predicts.
"So that means 880 will be very busy. Folks who travel north will get gummed up at the Golden Gate Bridge on Saturday from 11 a.m. to 7 p.m. and southbound out of Marin County on Monday."
Caltrans has posted warnings of the bridge closing on electronic freeway signs as far south as Southern California and as far north as the Oregon border.
The wild card is the holiday. Traffic is always a crawl on I-80 as people return to the Bay Area on Labor Day. Will drivers heed the doom-and-gloom predictions and adjust their plans?
"If people plan ahead, take transit, leave early, take those days off, too, it might be manageable." McConnell said. "But I've sadly noticed that many people don't pay attention to us no matter how often and on how many different platforms the information is available."
This week, stand on the platform and pay attention.
Contact Gary Richards at 408-920-5335.