SAN FRANCISCO — For decades the San Francisco-Oakland Bay Bridge has been considered, when it is considered at all, as a headache for commuters and a place not to be in an earthquake.

But that reputation is set to change Tuesday night when the artist Leo Villareal will switch on what is being billed as the world’s largest L.E.D. light sculpture. The public art installation, “The Bay Lights,” will illuminate the bridge’s 1.8-mile western span with 25,000 undulating white lights.

“My inspiration comes from the motion around the bridge, the kinetic activity of boats, water, clouds, traffic,” Mr. Villareal said.

From a distance, it will appear as a shimmering illuminated mass, but Mr. Villareal controls each light individually with a software program he developed. He turns the whole thing on and off from his laptop.