I have no idea if this video is accurate, but it is fun to watch.
The engineering & structural issues are enormous and this video minimizes many of them.
We worked for about three years on the rehabilitation of the north abutment (including the time Spielberg was "destroying" the bridge for his movie "War of the Worlds"....Tom Cruise was spotted by the crew several times, as his character lived in Bayonne) .
It would seem to me it might be better to raise the entire arch from both ends, rather than reconfigure the deck. The engineering would be challenging, but I don't see why it couldn't be done.
Tiz a good thing I am not a mathematics guru.
But I see physical structural uncertainties of changing the load within the existing arch.
But, I'll stick to my knittin'.
DGG