General Knowledge · Question #2

When should you do an en-route inspection of your vehicle?

A. Within the first 50 miles, then every 150 miles or 3 hours, whichever comes first
B. Only at the destination
C. Every 500 miles
D. Only when warning lights illuminate

Correct answer: A. Within the first 50 miles, then every 150 miles or 3 hours, whichever comes first
Explanation: Federal regulations (49 CFR 392.9) require checking cargo and securing devices within the first 50 miles, then every 150 miles or 3 hours.

Why this question matters on the General Knowledge exam

This question is one of the 65 we have for the General Knowledge CDL knowledge test. The official AAMVA Commercial Driver License Manual chapter on General Knowledge covers exactly this topic, and most state DMV exams pull from the same chapter. Memorizing the right answer is fine for passing, but understanding the underlying rule is what keeps you safe on the road and out of trouble with FMCSA inspectors.

If this topic gave you trouble, take the full General Knowledge practice test to drill it across all the related questions. We recommend reading every explanation, even on the questions you got right, because the manual phrasing in the explanation often shows up word-for-word on the real exam.

Take the full General Knowledge practice test →