MBuck,
I've made two trips up/down the ALCAN Highway. The last trip was Sep 2003. I plan to head back the first part of Jun 2005. I'm taking my boat back up there to sell to a friend of mine. The boat is better suited for the waters (Cook Inlet/Prince William Sound) up there than the lakes around here (Oklahoma).
The highway was in pretty good shape (relative to my first trip in 1994), approximately 80 miles of road construction. As mentioned there are frost heaves, but the bad spots in the road are usually marked with warning signs... The trip I made in 2003 went without experiencing any problems, no flats, etc. In fact, some of the highway, moving from Colorado to Oklahoma, felt rougher then the ALCAN.
The Mile Post is a valuable tool to use for planning your trip. Make sure you have a passport or an original copy of your birth certificate when you enter into Canada. If you take a firearm (no pistols allowed, just long-guns) you'll have to register it with the Canadian Government and pay a fee to transport through Canada. The fee is good for one year. Some of this may have changed since 2003, I need to go to their website to get updated before I make my trip.
It's a beautiful drive. You'll see lots of wildlife. Take a movie camera and plenty of film/flashcards for a 35mm/digital camera. Have them ready at all times. Keep an eye out for crazy tourists that stop in the middle of the road, without warning, to stop and take pictures... lol.
Good luck and enjoy your trip! If you've found out any info on identification requirements and gun restrictions, please let me know. Thanks.
Dwayne