Feel safe on that bridge?

Rinaldo Nicholson from VDOT thinks you should. “I know that our bridges are safe,” he is quoted as saying in this WTOP article. Perhaps, or perhaps just not too unsafe. I spent some time yesterday digging through the federal highway system’s online information on deficient bridges but it didn’t have good breakout data on WHICH bridges those were in that chart. There’s more specific info here but I lost interest at the point where I’d have to write perl script and a google maps mashup to parse out specific locations.

Fate, thy name is Andrew Sullivan, who linked to this 1994 Atlantic article about deficient bridges. The article is a little dated but it points out that in the coming decade – ie, between now and then – a lot of WW2 era bridges would need major repairs. I’d say the odds of there being a notably positive improvement in those stats are slim.

To give you an idea what you’re looking at (click the image or view the article for a proper key) the map section I’ve cut out here shows mostly green all around us, indicating that between 5 and 18.9% of the bridges in that area are ‘structurally deficient.’ SD is a grouping that could mean something very serious or might just indicate there’s a weight restriction on a span. However the salient point, I think, is that as many as 1 in 5 of Virginia’s bridges have been flagged as worthy of concern and potential upgrade. Not sure what Nicholson’s position is on that.

Another way of looking at it is fracture-critical steel truss bridges, which FHWA yesterday called upon all the states to examine. DC doesn’t have any, Virginia has 13 and Maryland 19. I’ll save you the googling – fracture critical indicates that there’s a span which, if it fails, does not have other spans capable of supporting that span’s weight, likely resulting in collapse. Presumably a fracture critical bridge is one which has one or more such spans.

Anyone who comes across some data more clearly identifying where the SD or FCST bridges in our area are, by all means post a comment.

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