I wondered, but could find no info
I think the build date for this bridge is inaccurate, based on the design of the bridge, and the traffic estimate coming from before the "build date" of 1991. A bridge appears at this location on the 1949 topographical map, so I would assume this bridge is at least that old.
Roger that, David. I ride by this bridge somewhat frequently on my motorcycle, but I always pay more attention to the old railroad trestle right up the bayou ;) Wish I had pictures of it!