SAN FRANCISCO — There was no public celebration with tens of thousands of pedestrians and fireworks in the ceremony marking the new, $6.4 billion eastern span of the San Francisco-Oakland Bay Bridge on Monday. Instead, after years of delays and cost overruns, the inauguration of the one of the state's most expensive public works projects was marked with a relatively low-key event.

"People are tired, but everyone's very excited," bridge spokesman Andrew Gordon said on Monday morning. "It's kind of this last lap so to speak, the last leg of this marathon. We are all looking forward to getting to the finish line."

The bridge was scheduled to open to traffic by 5 a.m. on Tuesday, but officials at the ceremony said the bridge would open some time tonight.

The new section of bridge, designed to make the span safe during earthquakes, has been under construction for almost a decade and follows years of political bickering, engineering challenges and cost overruns. It replaced a structure that was damaged during the 1989 Loma Prieta earthquake.

In March, more than two dozen rods used to anchor the roadway to important earthquake safety structures cracked after they were tightened. The discovery threatened to delay the bridge's opening by months.

The bridge will open with a temporary fix for the broken rods while the permanent repair, expected to be completed in December, is being installed.

Transportation officials approved the temporary fix last month and voted to open the bridge as originally planned around the Labor Day weekend.

But Gordon said on Monday that there was not enough time for a public celebration.

Plans for such a celebration originally called for a bridge walk with more than 100,000 people, fireworks, a half marathon and a concert.