(Updates with light morning rush hour, first cars to cross bridge)
By Laila Kearney
SAN FRANCISCO, Sept 3 A San Francisco Bay crossing that ranks as the world's largest self-anchored suspension bridge was put to work on Tuesday, with thousands of rush hour commuters traveling the span after it opened six years behind schedule and five times over budget.
The new eastern section of the San Francisco-Oakland Bay Bridge, which cost over $6 billion to build and is one of the busiest spans in the United States, opened late on Monday night.
Morning rush hour traffic was lighter than usual but the bridge is expected to accommodate 280,000 daily commuters, San Francisco police said.
The San Francisco-to-Oakland bridge had been shut to traffic last Wednesday to complete construction and build connections from the new eastern stretch to the existing toll plaza and the bay's Yerba Buena Island, before reopening the entire bridge.
The single-towered, 2,047-foot-long (634-metre) main span is more than twice the length of the previous record holders, Japan's Konohana Bridge and South Korea's Yeongjong Grand Bridge, according to the Structurae engineering database.
A self-anchored suspension bridge, the span has its main cables fixed to its deck, while a traditional suspension bridge is anchored to the ground.
The opening follows years of delays prompted by design disputes, financial struggles and safety issues. It also comes two decades after its predecessor partly collapsed in a 1989 earthquake.
California Highway Patrol officers on motorcycles and drivers of several vintage cars, including a 1930 Model A Roadster, were the first to cross the bridge before it opened to the public, said John Goodwin, spokesman for the Metropolitan Transportation Commission.
In March, a survey found that 32 of more than 2,300 steel rods used to help the 2.2-mile (3.5-km) eastern span of the bridge withstand earthquakes were broken.
The cost of the retrofitting was estimated between $5 million and $10 million. Placeholder plate stabilizers are being used to keep the bridge open before the rods are permanently replaced in December.
The bridge features a single 525-foot (160-metre) tower and a bicycle path, points of contention when the bridge was being planned. It will take about three years to demolish the old span, bridge officials said in a statement.
The eastern section of the bridge reaches from Yerba Buena Island to Oakland. The western stretch links downtown San Francisco to the island.
The east span includes eastbound and westbound traffic on side-by-side decks. The west span will continue to have decks placed above and below one another. (Additional reporting by Barbara Goldberg in New York; Editing by Alex Dobuzinskis and Lisa Shumaker)