Road construction: the roads have generally been good. I had to wait twice for 30 minutes at construction sites. I have come across numerous patches of road under repair that were gravel and dirt. They generally weren't an issue unless they were wet, then you felt the bike squirming a bit. On the Alcan there were long stretches of this, some up to 2 miles. If you stay in the tire grooves a street bike will make out fine as long as you slow down.
I have crossed a lot of wood plank and steel deck bridges with no issues. The long Teslin bridge had me squirming quite a lot, but a loose grip and a straight line and I made it ok.
Tires are Continental TKC70S an 80/20 road/trail tire. It is holding up well and hope to make the entire trip on them. There is some cupping on the front but it doesn't effect the performance. They worked pretty well on the Salmon Glacier road which was in real bad shape in some sections.