CDL · Logbook & ELD (Hours of Service) · Brazil
Logbook & ELD (Hours of Service) for the CDL Exam — Brazilian candidates
5% of the CDL test plan. Hours-of-service rules limit driving to 11 hours within a 14-hour duty window after 10 hours off; ELDs (Electronic Logging Devices) automate enforcement. Calibrated for Brazilian candidates.
For candidates aiming to clear this exam on the first attempt, the difference between Band 6 and Band 7+ — or "passing" and "comfortable margin" — usually comes down to fluency on a small number of high-leverage topics. Logbook & ELD (Hours of Service) sits at roughly 5% of the Commercial Driver License content distribution — 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. Pass rates for the CDL are published annually by the awarding body and vary by cohort and locale. For Brazilian candidates preparing for CDL, the calibration of study to local context matters: ENEM is Brazil's national entrance exam. For international study, IELTS and TOEFL dominate; CDL US licensure is a growing cross-border opportunity.
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).
- 5Brazilian candidates preparing for CDL should account for visa-processing timelines if testing abroad — most U.S. test centres require a B1/B2 visa appointment scheduled 90+ days in advance.
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.
Frequently asked questions
Are paper logs still allowed?
What is the CDL pass rate for Brazilian candidates?
How long should Brazilian candidates study Logbook & ELD (Hours of Service) for the CDL?
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