The San Francisco-Oakland Bay Bridge is scheduled to close to traffic for five days this Labor Day weekend, for final construction and a two-day celebration. Officials are planning a walk across the bridge, which normally has no pedestrian traffic.  It's estimated that could draw 125,000 people.

At a meeting of the Bay Area Toll Authority, event planner Mark Guelfe said getting that many people ticketed and over the bridge would take meticulous planning.

"We'll be unloading about 300 buses an hour for 8 hours on Monday, Labor Day," Guelfe said. "That's one bus every 12 seconds."

Some committee members balked at the $5.6 million public price tag, which would just cover the walk. Participants in a planned run and bike ride would have to pay their own way. Organizers are looking for private sponsors for a fireworks show to be seen around the bay.

The eastern span of the bridge is being replaced for seismic safety.  A portion of the upper deck collapsed on to the lower desk after the Loma Prieta earthquake in 1989.  Construction on the replacement span began in 2002.