Home › CDL Practice Tests › Air Brakes Questions › Question 191
What is a safe speed on a downgrade based on?
- A.The total weight, length and steepness of the grade, road and weather conditions, curves, and the condition of the brakes
- B.Only the posted speed limit for cars
- C.The speed of the fastest truck ahead of you
- D.The highest speed your engine can reach in top gear
Correct answer
A. The total weight, length and steepness of the grade, road and weather conditions, curves, and the condition of the brakes
Why
A posted limit does not know your weight, brake condition, or how long the grade runs. Professional downgrade speed is the speed you can hold and stop from under the actual conditions, not a number copied from traffic around you.
Manual topic: Air Brakes - Downgrade Braking · From the Air Brakes practice bank (AB-191).