OAKLAND — As Bay Area commuters trudged through the second day of a BART strike, they received some good news Tuesday: labor negotiations were set to resume later in the day as Gov. Jerry Brown sent in two top officials to help spur a deal.

After a 36-hour break at the bargaining table, BART management announced it would meet at a neutral office with mediators and union leaders in another attempt to hammer out a new contract.

Neither side has budged on key compensation issues since BART’s labor deal expired late Sunday, which ignited the agency’s first strike since 1997 and left the 200,000 people who ride BART daily to find another way to get around. Neither side was ready to offer a new proposal publicly heading into the labor talks, which were set to resume at a Caltrans office in Oakland at 6 p.m.

Still, just a meeting is the largest sign of potential progress since the strike began.

“There’s been no conversation. So I think seriously getting back to talking is the first step that had to happen,” BART spokesman Rick Rice said. “I’m hoping we can make a lot of progress.”

Late Tuesday, BART and the union that represents 200 supervisors and professional staff reached a tentative agreement. If approved by workers, members of the local American Federation of State, County and Municipal Employees would go back to work immediately, though the return of train service is still dependent on BART reaching a deal with the two larger, striking unions that represent 2,300 line-level workers.

The Brown administration, which has declined to issue a 60-day cooling off period to delay a strike, had previously urged both sides to reach a deal but called in extra firepower Tuesday.

“At the California Labor Secretary’s urging, all parties are returning to the bargaining table tonight,” said Brown’s spokesman, Evan Westrup. “To facilitate discussion between BART and its unions, the state is sending in two of its top mediators.”

Anita Martinez, chair of the Public Employment Relations Board, and Loretta van der Pol, chief of the State Mediation and Conciliation Service, will be taking over for two lower-ranked mediators that had been assisting the last two weeks.

In addition, BART Board President Tom Radulovich called a special closed-door meeting for Wednesday morning to discuss the labor talks. BART officials said the meeting is a chance to update its elected leaders on the latest talks, as the board must approve any agreement the agency’s executives reach at the bargaining table.

Union officials did not return multiple calls and emails requesting comment but sent a letter to state officials Tuesday blaming management for stalling.

“Our BART workers are intensely proud of the work they do,” the letter from leaders of the local Service Employees International Union said. “They’ve helped build one of the fastest-growing and highest-rated public transit systems in America. They’re committed to the work they do and would love to return to the job.”

Tuesday commute

The nation’s 5th-largest rail line doubled from 18 to 36 the number of chartered buses that would pick up commuters in the East Bay and take them to San Francisco, and adding a stop in West Oakland. Even still, by 7 a.m., the buses at the El Cerrito del Norte, Walnut Creek, Dublin/Pleasanton and Fremont stations were sold out — an hour earlier than the day before — and the West Oakland stop was set to reach its capacity by 8 a.m.

“When I got here at 4:45 a.m., there were people in line all along the side of” the road, said Ernest Cameron, a BART construction engineer who helped supervise bus passengers who lined up early to wait at the Walnut Creek station. “I asked the person in front of the line when he got here and he told me 3:45 a.m. So, we’ve been overwhelmed by the number of patrons.”

The last bus left at 7:42 a.m., leaving dozens of frustrated people stranded.

Dmitriy Dvoryan, a 31-year-old Walnut Creek resident, decided to drive after the shuttle sold out, but asked his three passengers for $5 each to contribute toward gas. He also told one young man with a cigarette that he would give him a ride if he didn’t smoke in his car.

“No problem,” the man said, dropping the cigarette to the ground and getting into the back seat. “You’re a lifesaver, man.”

Problems weren’t as bad on the roads, however. At the California Highway Patrol’s Traffic Management Center, Officer Ron Simmons said traffic on the three most impacted corridors, all going west in the East Bay — Interstates 80 and 580, and Highway 24 — was about the same Tuesday as the day before. Officials at 511 had similar observations.

“The only real difference that I noticed was the Fastrak lanes for the (Bay Bridge) toll plaza were backed up,” today Simmons said. “Yesterday, they weren’t.”

Simmons said the back-up on the Bay Bridge corridor extended to Richmond, the traffic on the I-580 route went back to San Leandro and the Highway 24 congestion stretched past the Caldecott Tunnel to Lafayette.

CHP Sgt. Diana McDermott called the first two days of the strike similar to a heavy commute day, as many displaced BART riders hopped on alternative transit or stayed home, alleviating the worst of the traffic nightmares that have been feared.

If a strike continues, traffic for the rest of the week is expected to be much lighter because of the holiday, though vacationers using Wednesday afternoon as getaway day for Fourth of July travel could make the Wednesday evening drive rough.

What’s at stake

Business groups said the strike is costing Bay Area companies $73 million a day in lost worker productivity from employees sitting in traffic. The same group, the Bay Area Council, estimated the environmental cost of the extra cars on the road at 16 million pounds of carbon a day, with drivers spending another $3.3 million to buy 800,000 gallons of gas each day. And transportation officials are spending $20 million in BART taxpayer funds to beef up transit service, staff traffic centers and deploy extra CHP cruisers.

Politicians, including Gov. Jerry Brown, San Francisco Mayor Ed Lee and several Democratic state lawmakers, have urged management and unions to reach a deal, to no avail. On Tuesday, Lt. Gov. Gavin Newsom, state Controller John Chiang, and Insurance Commissioner Dave Jones sent both sides a joint letter that spreads the blame and urges them to try harder.

“It is our collective opinion that, so far, you have fallen short,” the letter says.

BART employees — including management and nonunion workers — earn an average of about $83,000 annually in gross pay, contribute nothing toward their retirement and $92 monthly to health insurance. Their pay and total compensation are both the highest in the Bay Area among transit agencies.

BART has offered an 8 percent pay hike over four years and wants workers to pay more toward their medical and pension benefits. The local Service Employees International Union and Amalgamated Transit Union, which represent more than 2,300 train operators, maintenance employees and other blue-collar workers, are looking for a 23 percent pay bump and are willing to contribute more toward benefits, just not as much as management wants.

Even though BART is subsidized by taxpayers, it still loses money when it’s not operating because of other built-in costs that still need to be met even when the system is idle. BART loses $8 million in passenger fare and parking revenue each week it is shut down, and even with saving money on labor and other operating costs, it still loses a net of $3.9 million a week, or $560,000 a day, BART says.

Meanwhile, AC Transit reported more progress in its labor talks and a threatened strike by workers has yet to materialize since the bus line’s labor deal also expired late Sunday.

Staff writers Denis Cuff, Mark Gomez, Theresa Harrington, Brittny Mejia and Thomas Peele contributed to this report. Contact Mike Rosenberg at 408-920-5705. Follow him at twitter.com/RosenbergMerc.