(CNN) -- — After two days of strikes that have stranded 400,000 daily commuters in California's Bay Area, officials from the transit unions and transit authority planned to start negotiations Tuesday evening.
The meeting is expected to start at 6 p.m. (9 p.m. ET), said Rick Rice, a spokesman for Bay Area Rapid Transit, known as BART.
"We're just very glad to be going back to the table and start moving forward so we can get workers back and trains rolling," Rice said.
Antonette Bryant, the president of one of the two striking unions, Amalgamated Transit Union Local 1555, said the "ATU is hopeful that this evening's meeting with the district will be extremely productive."
The strike began at midnight Sunday after union leaders walked out of negotiations with BART hours before their four-year contract was set to expire.
For a second day Tuesday, no BART trains were running.
"It's created quite a traffic jam out here in the Bay Area and it's unnecessary," Rice said. "We should have been talking still, not resuming talks."
As the shutdown entered its second day, a conservative estimate put the cost at $73 million per day, the Bay Area Council Economic Institute said.
That figure comes only from lost worker productivity and does not include overall lost economic activity, "which could add tens of millions of dollars," council President Jim Wunderman said.
The dispute centers on pay and benefits.
Unions asked for a 21% pay increase. BART initially offered to increase salaries by 4% over four years, but later proposed an 8% increase; that was on top of a 1% increase scheduled to go into effect Monday.
Roxanne Sanchez, president of the other striking union, Service Employees International Union Local 1021, said workers are fed up.
"Years of layoffs have affected public safety and services. Crippling cuts have not just made our jobs more difficult, but put undue strain on our livelihoods, our families and our communities," she said in a statement.
"Believing in good jobs that pay fair wages, offer health care and a secure retirement -- these are modest ideals. These are UNION ideals," she said.
BART is the nation's fifth-largest all-rail train system in the United States, with 44 stations in 26 cities that make up the Bay Area, according to the transit authority.
It handles more than 40% of Bay Area commuters, according to CNN affiliate KPIX.
A study last year found San Francisco among the 10 cities with the worst commutes.
CNN's John Branch and Holly Yan contributed to this report.