On Monday, construction crews in California slowly lowered a 1.4 million pound section of bridge onto a barge destined for a scrapyard:

(San Francisco Chronicle)

Appropriately, it was the reverse of an operation performed almost 80 years earlier:

(Derleth Collection, Water Resources Center Archives, UC Berkeley)

The Carquinez Bridge was doomed by its own success. It was opened in 1927 as two-lane bridge carrying a US highway between two small towns at the fringe of the San Francisco Bay Area. In the late 1950s, it was joined by a twin bridge to become part of the Interstate system. Today, the suburbs have spread well to the north and the east, and the freeway is a major commute route. The old bridge didn’t meet current earthquake codes, and, even with three lanes squeezed into it, it was too narrow. The replacement bridge opened in 2003.

80 years is actually a fairly long life for a transportation structure. There are older bridges and tunnels and rail lines, to be sure, but wear and tear and the demands of growth and ever heavier vehicles make most of what we build obsolete in only a few decades. Houston’s first five-level freeway interchange, for example, opened at the Katy Freeway and Beltway 8 in 1989. Work is already underway on replacing it. The state of the art will be rubble in less than 20 years.

Over the past 50 years, people like Jane Jacobs (who died yesterday) have made us more aware of historic buildings and much more dedicated to finding ways to save them. One of the milestones in that movement was the preservation of Grand Central Terminal. But transportation facilities that aren’t buildings don’t often get the same treatment. Often, they’re literally in the way of progress: the office building that would have replaced Grand Central could be substituted for with office space just down the street. It would be hard to move I-10. But even historic bridges that aren’t in the way — the Carquinez Bridge wasn’t — are routinely demolished.

I had a personal affinity for the Carquinez Bridge. I grew up only 5 miles away; it inspired me to be a structural engineer and even made an appearance in the essay that got me into Rice. But that bridge has greater significance as well. It was the first high-level bridge on the West Coast, preceding the Golden Gate by a decade. It was designed by one of the greatest American bridge builders, David Steinman. It remains a landmark in the history of bridge engineering. And by creating a link where there was none, it literally reshaped the San Francisco Bay Area. It was a truly historic structure. I could make similar arguments for the Beltway 8 interchange — what building would better exemplify Houston’s 1980s boom?

Were the Carquinez Bridge a building, it would still be standing. Yet it’s done more than any building to shape the cities and towns around it. Transportation isn’t some afterthought, some sort of routine infrastructure to be built and forgotten. It’s at the core of our civilization. I wish we thought of it that way, not just in remembering what we built but in planning what we are about to build.

(San Francisco Chronicle)

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