re: Causeway dethroned by ten miles; 34 mile bridge opens

Problem with the I-10 I-55 combo as a "bridge" is that while it is entirely elevated, it is NOT entirely above water, or even watery marsh. Key land areas include north of Pass Manchac, the I-55/I-10 interchange north of Laplace, and both sides of the Bonnet Carre spillway.

Another thing is that the only reason it's over "water" for much of its route was that it was easier to build it by dredging a canal and floating stuff in by barge. Look at aerial photos or look close when you drive it-- the only "water" (other than the spillway area, where it actually passes over the edge of Lake Pontchartrain) is in the areas below/around the elevated roadway itself.