The chances of a crash in the Alaska highway environment are probably much slimmer than being in my home state environment. There’s very little traffic, very, very few side roads and intersections, and with care, I think it’s fairly easy to avoid animal collisions. The possible exception there might be the Cassiar Highway, where the cleared right of way is narrow and I’m told there are more animals present.
I went 13 miles down the Cassiar in a foggy, steady rain and cold temperatures. The pavement there is the most coarse of any highway I’d been on. I feared my tires would wear too rapidly to be able to get me home, and I just plain wasn’t having fun. So I turned around and came back home via the Alaska Highway. I’ll save the Cassiar for another day.
I do think the chances of mechanical breakdown are higher in Yukon/Alaska, with the rough surface pavement, intermittent mini washboard effect, and gravel roads causing a lot of pounding, shaking, and vibration in the bike. You also have the chance of sharp rocks slicing tires. One member of my party picked up a sharp spike in a tire after I had separated from the group. I heard it was plugged temporarily and a tire replacement stop was schedule.