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Logbook & ELD (Hours of Service) for the CDL Exam

HOS violations are among the most common roadside-inspection failures. The 11-hour drive limit, 14-hour window, 60/70-hour weekly limits, and 30-minute break rule are tested on the General Knowledge exam and enforced via ELDs.

Locale-specific study guides

Pass-rate data, regulatory context, and study tips for Logbook & ELD (Hours of Service) all change by candidate locale. Pick your context:

Common failure modes

These are the patterns that cause most candidates to lose marks on this topic. Recognising them in advance is half the work.

!Confusing the 14-hour window (cannot extend) with the 11-hour drive limit
!Forgetting the mandatory 30-minute break after 8 cumulative hours of driving
!Missing the 34-hour restart eligibility
!Not understanding short-haul exception (150 air-mile radius, return to terminal)

Study tips

1Memorize the four HOS limits: 11 / 14 / 60 / 70 / 30-min break.
2Drill the 34-hour restart math: 34 consecutive hours off-duty resets the 60- or 70-hour clock.
3Practice ELD edit log sequence — drivers can edit only off-duty status changes; driving time is locked.
4Know the short-haul exception threshold (150 air-mile radius, return same day).

Sample CDL Logbook & ELD (Hours of Service) questions

These sample items mirror the format and difficulty of real CDL questions. Practice with thousands more on the free Koydo question bank.

1
After how many cumulative hours of driving must a CDL driver take a 30-minute break?
- A6 hours
- B7 hours
- C8 hoursCorrect
- D10 hours
Why this answer?
The FMCSA rule requires a 30-minute break after 8 cumulative hours of driving. The break may be off-duty, sleeper-berth, or on-duty (not-driving) status.

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