Its simple cost/benefit analysis. Here are a couple clues.
These mountains rise directly out of the water. Every mile of road would have to be blasted out of solid rock. Its just not needed. There is daily ferry and air service down to Juneau.
I'll trust you to take care of Pennsylvania I'f you'll trust Alaskans to take care of Alaska.
We built a road from Burma to China in similar terrain in WWII.
Beautiful photos. Thanks for sharing.