I did that road while on a 2 week trip back in the late '90s. That was when we had our '68 fishbowl GMC 40' x 8.5' converted bus. We had no jakes or retarder and a 2 speed Allison. I do recall the drive heading west was a bit hairy, as it felt like the brakes were getting hot. I was young and dumb then though and was probably going too fast. I would not be afraid of driving it today. The downhill drive is the only concern. I really don't remember how curvy it was, it was the downhill the made the most impression, but even then, it wasn't that bad.