The reason the bridge(s)at Tellico were built to the standards that they were was because they had to be built to DOT Highway standards. We tried to get a waiver on that. It didn't happen.
The money was going to disappear for the last one built so it had to be done in a rush or there would be no stream crossing whatsoever.
Don't think that any actions taken by the FS or any Gov't agency means anything. They are a bureaucratic bunch and once something is underway, it is out of their hands so they are on to the next issue regardless of whether the last one made sense or not.