Originally Posted by
Bike Jedi
I know I-70 coming out of the mountains has a 12% grade if I remember correctly, it's been a while, and that's a long run.
I think I-70 going up to the Eisenhower Tunnel maxes out at 6% or so. There are some non-standard grades on interstates that are somewhat steeper, but interstate highways are generally engineered to stay under 6%. Some of the non-interstate paved passes in CO might go up to 8% or so.
- Mark