Commuters who normally rely on the BART regional system were forced onto already-crowded roads on the fourth day of the strike, backing up traffic well before dawn.
Bay Area ferry operators also reported major increases in passenger traffic on trips to San Francisco but most passengers turned to vehicles to get to work.
Traffic on the heavily traveled San Francisco-Oakland Bay Bridge started backing up at 5 a.m., according to the San Francisco Chronicle newspaper.
By 6 a.m., traffic headed to the bridge was backed up on State Highway 24 beyond the Caldicott Tunnel through the Oakland hills, the newspaper said.
"They have us hostage," commuter Richard Cupp told the newspaper, referring to the strike-shuttered transit system.
Cupp said he left before 6 a.m. from his home in Alameda but his regular half-hour drive to San Francisco still took nearly an hour.
"BART management had plenty of time to work this out," he said. "I'm disappointed."
Jamaudra Shepherd of Oakland told the Chronicle she caught a regularly scheduled early morning bus to San Francisco near the Grand Lake Theater.
"It's just really tedious," Shepherd said.
"I have to leave 90 minutes early, and I get home an hour later — I'm really over it."
But there appears to be some movement toward a settlement that would reopen the system, the newspaper said.
BART officials said Monday that they were open to resuming negotiations with the three striking unions if a team of federal mediators was willing to return, and planned an afternoon closed-door meeting to discuss the strike.
Management also was expected to discuss Saturday's accident that killed two workers inspecting tracks near the BART station in Walnut Creek.
The two were struck by a four-car train being used to train management personnel to operate the largely automated system should the strike continue.
More than 2,000 workers walked out Friday morning after negotiations broke down over BART management's insistence on changes to rules governing work assignments and shift lengths.
A long list of monetary issues that had been the subject of months of negotiations apparently have been resolved, including increases in worker contributions to health care and pensions.
The BART system links dozens of Bay Area cities with San Francisco and Oakland.