Gotta be the Charles Brown Rd. Bridge. US80 wouldn't have been on a one lane 11.8 foot wide bridge, would it?
This one is a puzzler, since Old 80 ran between Delhi and Tallula, and it's course seems to be north of Judd bayou. In fact, Old 80 appears to be only a short abandoned section just south of present 80 near Delhi. Look at Delhi in Bing and you will see a road ending at the river named Country Club Rd/Old US 80, and named Geddis Rd east of this unnamed river. The bridge is gone.
Bing imagery does show an iron truss just west across the river from the coordinates cited here.(+32.37000, -91.34333) It is on Charles Brown Rd.
The most likely scenario is that there is a mistake in the NBI, and the Charles Brown Rd. bridge is the correct one. That's my take on it anyway. There are only two other trusses on the NBI, and they are correctly placed.
Try this site for info and pictures on US80:
http://home.comcast.net/~bygonebyways/louisiana_80.htm
And this one for the FHA's description of US80.
Quebec Rd. looks to be a possibility since it's a very straight road leading to Tallulah. It crosses the bayou and appears to have a new bridge.
Can someone post updated GPS coordinates? I cannot find this bridge which was supposedly rehabilitated in 1999. The only truss bridge over Judd Bayou is clearly closed and has been for a while....