The air brake lag distance at 55 mph on dry pavement adds about ____ feet.
Answer: A
32
Be aware of driving conditions and how they affect your ability to stop. Even under ideal driving conditions, air brake lag will result in an additional 32 feet of stopping distance when traveling 55 mph for a total of more than 450 feet. Allow for additional stopping distance when conditions are less than ideal.
All choices
- A32
- B52
- C12
Why the other answers are wrong
B. 52
Choice B is wrong because 52 feet overestimates the air brake lag distance at 55 mph on dry pavement.
C. 12
Choice C is wrong because 12 feet underestimates the air brake lag distance at 55 mph on dry pavement.
CDL Air Brakes Test Info
Questions on Exam
25
Passing Score
80%
Time Limit
Typically 30 minutes; varies by testing location
The Air Brakes test content is federally standardized, so this question applies in every state. Age limits, fees, and testing procedures do vary — check your state's CDL requirements.
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More CDL Air Brakes Practice Questions
- The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below ____ psi.
- Characteristics of dual air brake systems include:
- Which component of the air brake system cuts-in at 100 psi to allow the air compressor to run?
- The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks fall below ____ psi.
- The safety valve is set automatically when pressure is: