A little off-topic (as far as states/regions go), but I did email some people at UDOT (Utah), and they do have some documents considering a Hurricane bypass that would connect UT-59 with the Southern Parkway.
Again, these are just talks, but it's rather significant that UDOT seems to be considering a different route from UT-59 to the Southern Corridor (and thus St. George and I-15) while avoiding the current route off the Hurricane Hill (a steep section of road where you drop off the plateau into Hurricane on UT-59).
I'll provide the documents later.