Work on the project, which will cost $350 million, is already underway. It is the equivalent of an engineering tight rope act.
Crews will delicately slice through a 300-foot stretch of the eastern span of the Bay Bridge near Yerba Buena Island, roll out and destroy a massive chunk of seismically unfit roadway, then slide in a temporary new span.
It will all take place 150 feet in the air and in record time.
"This is done in a weekend's time, three or four days. We're still working on the schedule right now," said Senior Bridge Engineer Bill Casey.
It will happen over Labor Day weekend. In order to pull off this engineering feat the entire Bay Bridge will be shut down. Transportation officials are already warning drivers to brace for the traffic nightmares
"The other Bay Area Bridges will remain open, and your detour routes… everyone knows them by now," said Caltrans spokesman Bart Ney.
When the bridge shut down in 2007 for the ongoing bridge /*retrofit project*/ the impact was felt around the region.
"If people come out in force in their cars, they will sit in traffic," said Mary Curry with the Golden Gate Bridge District.
But, this time around the delays could last longer than the holiday weekend. The new span will have a 40 mph speed limit. That is ten miles slower than what is currently allowed. It will take commuters some getting used to.
"The reduction from 50 mph to 40 mph in this particular location shouldn't affect commute traffic because if you can actually get to 40 mph during a commute, you're doing pretty good on the Bay Bridge," said a bridge engineer.
The entire retrofit will not be complete until 2013. But, once it is done, engineers say events like the bridge collapse during the 1989 earthquake should not happen again.
Still, those working on the new project concede that the temporary span will not be any safer than the old bridge that 280,000 vehicles drive on every day.
"For the detour itself you need to build something up to same level as the existing, if not a little bit better. You have the whole structure back there. If you're hit with a massive earthquake the rest of the spans are going to behave the way they are, and this is just a little bit better," Casey explained.
The new section will be a double-decker just like the current section, but it will have a slight curve as it approaches the Yerba Buena Island Tunnel. That curve is the reason for the new 40 mph speed limit.