I've always wanted to see the Brooks Range and northern Alaska. The Dalton Highway was built for and serves the oil fields. It's about 400 miles long overall, but on this trip we went no further than Galbraith Lake, on the north side of the Brooks Range, about 275 miles. It was paved for about a quarter of that distance, and a well-graded gravel road the rest of the way. All the stories we had heard of a bad road, or about huge trucks screaming through at 80 mph were not true.
We saw maybe 10 trucks a day, and most were going at moderate speed. The speed limit is often 50pmh, though sometimes potholes, rough ground, steep hills, or sharp turns requires that you go slower.
My brother Dave and I rented a 4WD pickup truck with a camper shell at GoNorth in Fairbanks. The only time we used the 4WD was the steep climb up the southern side of Atigun Pass, which was wet and there were some snow flurries. We spent a week (sept 15-22, 2009) on the road and had 4 days of clear sunshine, and only a bit of rain and snow.