Both sides say they are committed to working through the weekend to avoid a strike.
"We are giving you a 72-hour notice of an impending strike if we are not able to come to agreement with the district by midnight Sunday," said Antonette Bryant, the president business agent of ATU Local 1555.
No one wanted to hear that BART and its unions are struggling to reach a deal.
"This is truly a sad occasion. I don't think I've ever been involved in an effort that we tried so hard not to have to strike," said George Popyack, the chief negotiator for AFSCME Local 3993.
BART is disappointed with the strike notice saying it will only stall the process of reaching an agreement.
"We've increased our salary offer and reduced our request on pension and benefits. Meanwhile, they're still looking for a 20-plus percent pay increase. We need a more reasonable contract for the future of this system," said BART spokesman Rick Rice.
Josie Mooney is one of the chief negotiators for the SEIU. She says they will continue bargaining 24/7 to try to avoid a strike, but that BART negotiator Thomas Hock isn't making it easy.
"Whatever instructions Mr. Hock has gotten from the general manager has been to avoid bargaining with us in good faith," said Mooney.
Hock says that just isn't true.
"We've dropped a lot of things, we've agreed to a lot of things, so how is that bargaining in bad faith?" said Hock.
Medical, pension and wages are the sticking points in the negotiations. And with the strike deadline looming, the Bay Area Council -- representing local business owner -- is now weighing in aalling on the unions to accept BART's latest contract offer.
"We need to all work together and I think that on balance that it's a fair package that's been offered given all of the circumstances," said Jim Wunderman, the Bay Area Council president and CEO.
But BART directors who've been observing the talks tell us the negotiations are bizarre and personalities are getting in the way. So if an agreement is to be reached by Sunday night, it's clear something will have to change.
The rally in Oakland got a boost from actor Danny Glover, who is a union supporter.
"We want BART to negotiate on solid principals," said Glover.
If there is a strike, BART is hoping to have up to 95 buses available to make limited runs from the El Cerrito, Walnut Creek, Dublin/Pleasanton, Fremont and West Oakland stations. Service from Concord and San Leandro may be added as well.
Bay Ferry will make additional trips from Oakland and Vallejo. Overflow parking will be available in Alameda.
Golden Gate Transit will have not have additional service, but two of their boats will be used by Bay Ferry. Carpool lane hours will be extended, like they were last time, from 5 a.m. through 7 p.m.
If a strike happens, transportation officials will be handing out $5 gift cards to evening casual carpoolers in San Francisco.
Tense talks continue Thursday between BART, unions
Earlier on Thursday the tension was so thick at the BART contract talks, people walked out with some very grim faces.
The union leaders left the talks for a rally that started at Frank Ogawa Plaza and ended up at the BART headquarters at Lake Merritt. They left saying, "No comment, see you at the rally."
But if BART directors James Fang and John McPartland are any indication, talks are not going well at all. They were sat in the talks for two hours as observers. As they left they spoke to us off camera. They called the talks bizarre and that they think personalities are getting in the way. The two sides still have not gotten to talking about the major hot potato topics like medical, pension, and wages. Fang said in his 23 years as a BART director, he's never seen the board left so out of the negotiations process.
BART rolled out its charts Thursday, showing what workers at a long list of other Bay Area public employers pay into their pensions, while BART workers pay nothing.
"We're just trying to play catch up with what everyone else had already figured out how to do here in the Bay Area," BART communications manager Alicia Trost said.
The transit agency says there's no line the sand, but it sounds like there is, on pension and medical benefits; benefits that have to be reined in if BART is going to survive and thrive down the line.
"There's no question that BART employees should get a pay raise," BART spokesperson Jim Allison said. "But contracts that continue to allow BART employees to pay nothing toward their pensions and a flat rate for health care, those contracts are no longer sustainable."
Thousands of BART riders are caught in the middle of the labor dispute, not knowing how to plan to get around next week. Just when they thought it was over, the transit agency's workers are gearing up to put the brakes on service once again. And BART riders are not happy.
Commuter Clarinda McElroy is working on putting together a carpool for next week.
"I haven't picked sides, but I think we need BART, because that's how we get back and forth to work all these years," she said.
Roger House drives to Oakland from Walnut Creek. He's also planning for a strike. When asked how it was the last time, he answered, "It was awful, it was double the time. And this time it's going to be worse, right, because it's going to be ten percent more."
"I feel frustrated," one BART rider said. "I just found out about that this morning and the last strike was really challenging."
Commuters with limited mobility and those needing assistance say getting around as it is is hard enough. But disrupting train service makes it close to impossible.
"This is hard times, we're all hurting, and so the service is needed desperately," commuter Beverly McAllister.
Commuters are directing their anger at both BART and its workers.
"But I imagine at some point the people who work on BART will accept the minimal," one commuter said.
Fellow BART rider Douglas McKay added, "Pay part of the pension, pay part of the health care, everybody else does."
Still, others believe a hardline approach would seal the negotiation deal quick, fast, and in a hurry.
"BART is overpaid and if I was on the board, what I'd offer them was you get a choice of a 25 percent cut, a 20 percent cut and if you don't like that, you're out the door," McKay said.
Director Fang off camera told us that he thinks these talks are even more contentious than those in 1997 that led to a six day strike.
If there is a strike, anyone expecting a short resolution should think again. Fang says he's heard it would be a minimum two weeks. The first week is when the public would crucify the unions and the second week is when they'd hate everyone, except then, BART would run out of money.
The two sides have until Sunday to reach an agreement, before thousands will be forced to find alternate routes around the bay.
Stay with ABC7NEWS.COM for updates on the looming BART strike and information on how to get around if the trains stop running. Follow us on Twitter, Facebook, and Google+ and download our news app for the latest news whenever and wherever you want.