I drove Hwy 58 nearly every day for 2 years when I was driving tankers. From about MP52 to the top I could only do about 25-27 mph. When you're pulling 105,000 lbs on a 6-7% grade, there ain't much you can do about it. So that's 12 miles of hill with cars stacking up behind. All I could do was use the pullouts when they came up, and wave at the passing motorists when they flipped me off.

I had a helluva lot more than 5 cars trailing me most times, including state cops, and I never received a citation.
IMHO, Hwy 58 is about the nicest highway through the Cascades, especially once they repaved it. I can make good time on it except for the stretch between Oakridge and the summit.