Atchafalaya Basin Bridge? You said NOLA, but I see trees on the sides of that one. Unless it's that one small part near the west end of the Bonnet Carre near LaPlace.
GPS tag looks like I was almost exactly halfway between Lafayette and Baton Rouge.
as soon as I moved it's like I wiped that whole thing from my memory. now I just drive thru it and remember how long it is haha