When I was dating the woman who so lost her mind as to move to Gunnison and marry me(1983,) I used to assume 3.5 to 4 hours for Durango-Gunnison.
Of course that was in Winter when the roads were clearer. When we went to Durango on our honeymoon that August it took about 5 hours. Bumper-to-bumper touristas in both lanes, Colona-Purgatory going 15 mph. Snow and ice weren't as much of an obstacle.[1]
Of course there was that one time I came around a corner on Coal Bank Hill and there was a rock the size of an easy chair in my lane, April '83 that was.
hank
It's ok to want to look at the scenery but that's why they put all those nice pull-offs alongside the road, so you can let people by!