Monday, August 06, 2007

Infrastructure Panic -VS- Reality

It's not a perfect world, not even in the United States. Today I heard Ed Schultz, commenting on the Minneapolis bridge collapse, state that this was a "systemic" problem and the entire process for reviewing bridge safety needs to be overhauled. One collapse and the world needs to be re-invented. Boloney!

Per Ed, there are 900,000 bridges in the U.S., 115,000 of which have identified structural issues. Listening to him, you'd think that most of them will likely collapse this year. He's wrong by about 115,000 bridges.

Scientists are not perfect. Doctors are not perfect. My spelling is not perfect. Bridge inspectors are not perfect. Even the people who check out the fabulously expensive space shuttle are not perfect. Unfortunately, we have tragedies caused by human imperfection all the time, despite our best efforts. We need to learn to live with them and not panic over isolated incidents, Ed Shultz.

This long bridge was a very complicated structure that was subject to many physical and environmental stresses. Surely it had some corrosion after 40 years of exposure to the elements, and some of the wearing parts, like bearings, had probably deteriorated. I expect the final report on this bridge will conclude that the collapse had no single cause but was the result of a number of interrelated deficiencies and perhaps an unusual stress at the time it collapsed. This kind of "domino effect" failure is extremely hard to predict, since no individual (inspectable) feature of the bridge was deemed a failure risk at the time of its last inspection.

Am I suggesting we do nothing in response to the collapse? No. We need to continue inspecting our infrastructure and writing readable and honest engineering reports about what is found. State governments need to prioritize their infrastructure spending and increase it if necessary. But now is not the time to throw out the baby with the bathwater. If we start getting a major bridge collapse every year, maybe I'll change my mind, but for now let's just grieve for those who lost their lives in a random accident. The bridge inspectors will be on heightened alert, and that is all we need to feel safe.

1 comment:

ThomasLB said...

I think people sometimes forget that there are 300 million of us here in America. There's a pretty good chance there's something awful happening somewhere to someone.

For most of us, though, things are running pretty well.