Is There A Deficient Bridge In Your Town?
The highway bridge that collapsed into the Mississippi River on Wednesday was rated as "structurally deficient" two years ago and possibly in need of replacement.How many other bridges score less than 50% on the National Bridge Inventory? You would think it would be easy in this internet age to find out ... but when you're dealing with the federal government, don't expect "easy." For starters, one page I found in the search of the Department of Transportation (DOT) database still had a navigation tab for the "Year 2000 Computer Problem."
That rating was contained in the U.S. Department of Transportation's National Bridge Inventory database. ...Many other bridges nationwide carry the same designation that the I-35W bridge received, [a Minnesota Dept. of Transportation spokesperson] said. ...
The deficiency rating is derived from a complex formula that evaluates many factors and condenses them into an overall score. A score of 80 percent or less indicates some rehabilitation may be needed; a 50 percent score or less indicates replacement may be in order.The I-35W bridge was rated at 50 percent.
But here's the table, Deficient Bridges by State. As you can see, it's hard to read, with column headings Area, SD Area, FO Area, Both AR, Count, SD, FR, Both. No legend is available, but there is a 124-page coding guide to the inventory which might be helpful. That's 124 pages. Fortunately, a Caltrans document tells me that "SD" stands for "structurally deficient."
The table reveals that there are 2,102 structurally deficient bridges in the lead-off state, Alaska, 2,994 in my home state of California, and for some reason, 6,299 in Oklahoma of all places -- the number one state for deficient bridges in the nation. In all, 73,746 bridges are in the"SD" column.
I poked around in the Caltrans web site, which was friendlier that U.S. DOT, but hardly Mr. Rogers Neighborhood. After a few clicks, I actually found a searchable database for deficient bridges in the state -- but again, it's not easy. It asks for bridge numbers, scour and paint criteria and other intimidating factors.
Fortunately, it let me search by a sufficiency rating of less than 50, the same as the I-35W bridge had, and I found three such bridges in OC. I've driven over all three -- they're small bridges on mountain roads.
Where are the federal bridges on the Interstate, the ones I'm really worried about today? They're not in this database; for that, I need to go to DOT.
Been there, tried that ... deficient database. So, I drive on faith. Diminished faith, but what other option is there?
Hat-tip: memeoranum; photo: Reuters