New Bay Bridge Span Dazzles As It Takes Shape

More than any architectural form, a bridge lets us glimpse the society that caused it to be.

We see the limits of what an era can build - the engineering chops - but also the values of the builders. One culture might put on lavish airs, another exalts efficiency above all else. A bridge that lunges into the unknown can't help but be different than one conceived with no grander goal than to shorten the commute.

That's why I'm at once dazzled by the emerging eastern span of the Bay Bridge, and not sure I buy in to all it represents.

The bridge-to-be reached a milestone Friday when a ship arrived with the first segments of steel for the 525-foot tower that will rise at the edge of Yerba Buena Island. From it, cables will loop down to cradle the twin roadways of the bridge. The target opening date is 2013.

Already, though, we can sense the scale of the $6.3 billion project that began construction in 2002.

Especially when viewed from the water. Or inside the span itself.

Both perspectives were available on a recent media field trip organized by Caltrans. We loitered on the 15-foot-wide path reserved for bicyclists and pedestrians (a subject for another column). Our boat idled alongside the steel trestles that will support the final half-mile of the bridge deck while the tower takes shape and the cable is woven into place.

But the aspect of construction that made the most startling impression was when Caltrans spokesman Bart Ney led us down metal stairs from the surface of the concrete viaduct into the hollow core that extends the length of the skyway.