what percent of grade is the steepest paved road?

Answer 1

My appologies for commenting on the comments.

38% grade??? That's damn steep!

I've been down (& up) Lombard St. in S.F. It is fairly steep but nothing I'd write home about.

I don't know about the others...

I used to plow a the streets where I used to live in Colorado. I don't know exactly how to calculate a grade % but I do know pitch & fall. The gnarliest street I had to plow has a 6 - 12 pitch. That means it dropped 6 inches for every foot it had in length. Every 10 feet it dropped 5. That's one steep SOB especially if you're sitting on top of 10 tons of iron trying to make it down in one piece. There were a few others that were nearly as steep but nothing like that three blocks.

Answer 2

I was thinking of Lombard Street in San Francisco which has a 16 degree maximum slope so its grade is 27%. But Filbert St is San Francisco's steepest at 31.5%.

I found a place that claims Baldwin St in New Zealand has a grade of 38% and is the steepest paved street. See "source" below.

Answer 3

Current codes typically allow a maximum of 15% grade. Anything steeper will not be approved if emergency vehicles are required.

Answer 4

technically, something like 160. That is, of course a very small portion, where the tires can roll right over it.

Answer 5

13%, there's the steepist road in the world in my suburb, you know it, wheelies bin kartings on!!!!!!!!!!!!!!!!! and bob sleding

Answer 6

9% is pretty steep