BTW - Alaska's other major unpaved road, the Denali Highway, is almost as extreme as the Haul Road (Dalton Highway) but arguably more dangerous. It is not maintained (i.e., plowed) for around nine months of the year, from early fall to late spring. People are strongly advised to avoid it during those periods. (The few who have tried have almost always died.)
Even though it's only one third the length of the Haul Road, it's more dangerous because of a lack of services and traffic. While services are (to put it mildly) sparse along the Haul Road, they are nonexistent on the Denali Highway. The Haul Road also experiences significant daily traffic year-around. On the other hand, most people are able to travel the entire length of the Denali Highway without seeing another vehicle, even when it's open. (People who camp along the Denali Highway report going a week or more without seeing another person.)
Since January, 1980, I have traveled just about every highway in Alaska. I have not tackled the Denali Highway, and probably never will, largely due to the risk involved. (This is surprising to people who know me because activities involving a significant degree of risk were routine for me, especially when I was younger.)
