what is the road regulation on gradients?

Question

In the US what is the regulation on the graded descent of roads?

Answer 1

2, 3, 7 and 8...

Answer 2

For maximum gradient, it depends upon the engineered speed limit and the terrain and the environment (urban or rural, mountainous, etc). Example:

Mountainous terrain with a speed limit of 40 mph, the max gradient is 8%

Mountainous terrain with a speed limit of 80 mph, the max gradient is 5%

On relatively flat terrain, it ranges from 5% @ 40 mph to 3% @ 80 mph.

Mountainous urban areas is 11% @ 50 mph.



If you are talking about driving down a steep grade, it is illegal to coast at any time. Coasting can lead to loss of speed control, loss of braking capacity and eventually an accident. Engine braking does a lot for downhill descents.

Answer 3

You must keep the car in gear, up hill traffic has right of way.

Answer 4

Your question isn't understandable. Are you asking what %grade is allowed maximum or what.