You are driving a 40-foot vehicle at 55 mph. The road is dry, and visibility is good.What is the least amount of space that you need to have in front of your vehicle?
Answer: A
5 seconds
The minimum safe following distance when driving is one second per ten feet of vehicle length, plus an additional second if traveling over 40 mph. Therefore, a 40-foot vehicle traveling 55 mph would require a minimum following distance of five seconds.
All choices
- A5 seconds
- B4 seconds
- C6 seconds
Why the other answers are wrong
B. 4 seconds
Four seconds is less than the required minimum following distance for a 40-foot vehicle at 55 mph.
C. 6 seconds
Six seconds exceeds the minimum required following distance but is not the least amount needed.
CDL General Knowledge Test Info
Questions on Exam
50
Passing Score
80%
Time Limit
Typically 60 minutes; varies by testing location
The General Knowledge 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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