OAKLAND, Calif. — The plan was to finish construction on the new eastern stretch of the San Francisco-Oakland Bay Bridge and open it on Labor Day. Then the existing bridge, which partly collapsed in 1989 during the last major earthquake here, would be demolished.

But problems surrounding seismic bolts in the new stretch and lingering questions about others have now presented California with two unattractive options for the most expensive infrastructure project in the state’s history. Under the assumption that the next major jolt could occur at any time, should the state delay the opening of the new bridge, which despite its imperfections is said to be more seismically resistant than its 77-year-old predecessor? Or should the opening go as planned, leaving some issues to be resolved later?

State transportation officials must decide by July 10.

“We are pushing for time against when the next earthquake will occur, and that’s why there’s this urgency about this,” said Amy Rein Worth, the chairwoman of the Metropolitan Transportation Commission, one of the organizations involved in the construction, and the mayor of Orinda, a city in the East Bay. “At the same time, there’s a strong feeling from all of us involved that we want to get it right.”

Officials are also under political pressure to finally wrap up a project that over the years has suffered from several construction problems and delays because of budget woes and political disagreements. The cost of the new stretch of the Bay Bridge — which handles about 280,000 cars a day and ranks among the three busiest bridges in the nation — has ballooned to $6.4 billion.