It's described on The Bay Lights website this way:
"The Bay Lights is the world’s largest LED light sculpture, 1.8 miles wide and 500 feet high. Inspired by the Bay Bridge’s 75th Anniversary, its 25,000 white LED lights are individually programmed by artist Leo Villareal to create a never-repeating, dazzling display across the Bay Bridge West Span through 2015."
Here's a video that gives you an idea of what the light show will be like. I can't wait to see it!
The Grand Lighting Ceremony is tomorrow night March 5, 2013 at 8:30pm PST.
For the curious who don't live in the Bay Area you can watch a one-hour LIVE video webcast online at the same time!
"Witness the birth of the largest light sculpture in existence! Join us for a one-hour, multi-camera live broadcast of the Grand Lighting by MediaOne, including a brief look at the “Making of The Bay Lights” and interviews with artist Leo Villareal and others instrumental to this amazing project."
For more details visit www.TheBayLights.org