Federal regulations are the legal backbone of commercial driving in the United States. Every time you sit behind the wheel of a commercial motor vehicle, a detailed set of federal rules governs how long you can drive, when you must rest, what technology you must use to track your hours, and what qualifications you must maintain to keep your Commercial Driver’s License (CDL).

On the CDL General Knowledge test, the Federal Regulations domain accounts for approximately 8% of the exam — roughly 3 to 5 questions. While that may sound small, these questions are among the most predictable and formulaic on the entire test. With focused study, you can virtually guarantee correct answers on every single question in this domain, making it one of the highest-return study investments you can make.

This study guide covers the four core pillars tested: Hours of Service (HOS) rules, Electronic Logging Devices (ELDs), Driver Qualification requirements, and CDL Disqualification penalties.

We’ll break down the exact numbers you need to memorize, the comparison tables that clarify confusing overlaps, the mnemonics that lock it all in, and the common traps the exam uses to trip you up. Whether you’re a first-time test-taker or refreshing before your exam, this guide gives you everything you need to master this domain.

Exam Weight & Topic Overview

The Federal Regulations domain represents approximately 8% of the CDL General Knowledge test. That translates to about 3–5 questions out of the roughly 50-question exam. While smaller than domains like Vehicle Inspection or Basic Vehicle Control, it punches above its weight because the questions follow highly predictable patterns — mostly numerical recall and category identification.

Here’s how this domain fits within the broader exam:

pie title CDL General Knowledge Test — Domain Distribution
    "Vehicle Inspection & Maintenance" : 14
    "Basic Vehicle Control" : 12
    "Shifting & Speed Management" : 12
    "Seeing & Communicating" : 12
    "Space Management" : 12
    "Night & Extreme Conditions" : 10
    "Emergency Maneuvers" : 10
    "Cargo Management" : 10
    "Federal Regulations & HOS" : 8

The four subtopics within this domain break down roughly as follows:

• Hours of Service Rules (~40% of domain questions) — HOS limits, break requirements, restart provisions
• Electronic Logging Devices (~20%) — ELD mandates, exemptions, malfunction procedures
• Driver Qualifications (~20%) — Age, medical, CDL, and training requirements
• CDL Disqualifications (~20%) — Major offenses, serious traffic violations, penalties, BAC limits

Study Strategy Insight: You can realistically master this entire domain in 2–3 hours of focused study. The questions are factual and repeatable — there’s no conceptual fuzziness or interpretation needed. Memorize the numbers, understand the categories, and practice a few scenario calculations, and you’ll be ready.

High-Yield Cheat Sheet

Before diving into the deep content, here’s your quick-reference cheat sheet. Pin this, screenshot it, or print it out.

mindmap
  root((Federal<br>Regulations<br>Cheat Sheet))
    Property-Carrying HOS
      11-hr Driving Max
      14-hr On-Duty Window
      30-min Break after 8hrs
      10-hr Off-Duty Reset
    Passenger-Carrying HOS
      10-hr Driving Max
      15-hr On-Duty Window
      No Specific Break Rule
      8-hr Off-Duty Reset
    Weekly Limits
      60-hr / 7-Day OR
      70-hr / 8-Day
      Carrier Chooses
      34-hr Restart
    ELD Rules
      Required for Most CMVs
      Exempt: Pre-2000 Short-Haul Driveaway
      Malfunction: Notify 24hrs Paper Logs 8 Days
    BAC Thresholds
      0.04 Percent Disqualification
      0.02 Percent Out-of-Service
    Major Offenses
      DUI BAC 0.04 Plus
      Leaving Accident Scene
      Felony Using CMV
      1st: 1-Year Disqual 3yr HazMat
      2nd: Lifetime
    Driver Qualifications
      Age 21 Interstate
      Valid Medical Certificate
      ELDT for New CDL Since 2022

Key Numbers to Lock Down:

• 11-14-30 = Property-carrying core (11 driving, 14 window, 30-min break)
• 10-15 = Passenger-carrying core (10 driving, 15 window)
• 0-4-2 = BAC thresholds (0.04% disqualification, 0.02% out-of-service)
• 34 = Restart hours (must include two 1 AM–5 AM periods, once per week)
• 60/70 = Weekly on-duty hour limits (7-day / 8-day)

Topic Connections

Federal Regulations don’t exist in isolation — they create the legal framework that touches nearly every other CDL domain.

flowchart LR
    FR[Federal Regulations<br>& HOS] --> VI[Vehicle Inspection<br>Inspection time = on-duty]
    FR --> CM[Cargo Management<br>Loading/unloading = on-duty]
    FR --> PE[Passenger Endorsement<br>Passenger-carrying HOS rules]
    FR --> HM[HazMat Endorsement<br>3-year disqualification escalation]
    FR --> SB[School Bus<br>Passenger HOS + extra rules]
    FR --> TV[Tank Vehicles<br>Property-carrying HOS applies]
    FR --> CV[Combination Vehicles<br>Property-carrying classification]
    FR --> BVC[Basic Vehicle Control<br>Practice time counts toward HOS]

Why This Matters: Pre-trip inspections count as on-duty time and eat into your HOS window. Loading and securing cargo counts as on-duty time. Even practicing your driving skills counts toward HOS limits. Understanding Federal Regulations gives you context for why time management matters across every aspect of commercial driving.

Most Important Connection: The HazMat Endorsement amplifies disqualification penalties. A first-offense major violation that normally carries a 1-year disqualification jumps to 3 years if you hold a HazMat endorsement. If you’re pursuing HazMat, pay extra attention to the disqualification rules.

Priority Matrix

Not all content in this domain is equally important. Use this priority matrix to focus your study time where it matters most.

quadrantChart
    title Federal Regulations Study Priority Matrix
    x-axis Low Exam Frequency --> High Exam Frequency
    y-axis Low Complexity --> High Complexity
    quadrant-1 High Priority
    quadrant-2 Watch Carefully
    quadrant-3 Review If Time
    quadrant-4 Background Only
    Property HOS Rules: [0.85, 0.6]
    BAC Thresholds: [0.7, 0.3]
    Major Offense Categories: [0.75, 0.5]
    Passenger vs Property Comparison: [0.65, 0.55]
    34-Hour Restart Conditions: [0.6, 0.7]
    ELD Exemptions: [0.55, 0.4]
    Driver Age Requirements: [0.5, 0.2]
    Disqualification Durations: [0.7, 0.45]
    ELD Malfunction Procedures: [0.5, 0.5]
    Weekly Limit 60 vs 70: [0.45, 0.35]
    AOBRD Phase-Out: [0.2, 0.15]
    Intrastate Age Variations: [0.15, 0.25]

Priority Table

Core Content Deep Dives

Pillar 1: Hours of Service Rules (49 CFR Part 395)

Hours of Service regulations limit how long you can drive and work to prevent fatigue-related accidents. These are the most-tested rules in this domain.

Property-Carrying Drivers (The “11-14-30” Rule)

Key Detail: The 14-hour window is consecutive and non-extendable. Even if you take breaks during the day, the clock keeps ticking. Once 14 hours have passed since you started your shift, you cannot drive — even if you’ve only driven 8 of your 11 available hours.

Passenger-Carrying Drivers (The “10-15” Rule)

Exam Tip: Use the P-L-U-S mnemonic:

• Passenger = 10 driving hours (one less than property’s 11)
• Longer window = 15 hours (one more than property’s 14)
• Under = no specific 30-minute break rule
• Shorter reset = 8 hours off-duty (vs 10 for property)

The 34-Hour Restart

The 34-hour restart lets you reset your weekly (60 or 70-hour) limits. Three conditions:

1. 34+ consecutive off-duty hours (no driving, no on-duty work)
2. Must include at least two periods between 1:00 AM and 5:00 AM (home terminal time)
3. May only be used once per 168 hours (7 days)

Exam Trap: A question might describe a driver taking a 34-hour break on Monday through Tuesday afternoon — with no early-morning off-duty periods. This break does not qualify as a restart because it lacks the required 1 AM–5 AM periods.

Pillar 2: Electronic Logging Devices (ELDs)

ELDs automatically record driving time, on-duty time, and HOS compliance data, replacing paper logbooks for most CMV operations.

Who Needs an ELD?

Most CMV drivers operating in interstate commerce must use an ELD. Key exemptions include:

Exam Tip: Use the M-A-P-S mnemonic: Manufactured before 2000, Agricultural exemption, Pre-2000 engine rule, Short-haul (100/150 air-mile).

ELD Malfunction Procedure

If your ELD malfunctions while on the road:

1. Notify your carrier within 24 hours of discovering the malfunction
2. Begin paper logs (Record of Duty Status forms) immediately
3. Continue paper logs for up to 8 days while the ELD is being repaired or replaced
4. Reinstall or replace the ELD before the 8-day period expires

You can continue driving — the ELD malfunction does not immediately ground you.

Pillar 3: Driver Qualifications (49 CFR Part 391)

To legally operate a CMV, you must meet minimum qualification standards.

Exam Tip: The key number for interstate driving age is 21. If a question mentions “interstate commerce” or “crossing state lines,” the minimum age is 21. Intrastate may be lower, but the federal minimum for interstate is always 21.

Pillar 4: CDL Disqualifications & Penalties (49 CFR Part 383)

Violations can result in losing your CDL driving privileges. The severity and duration of disqualification depend on the type of offense.

Major Offenses

Use the D-R-I-V-E mnemonic: DUI, Running (leaving scene), Illegal use (felony), Violating (CDL revoked), Endangering (fatal negligence).

Serious Traffic Violations

Key Distinction: Major offenses → 1-year/3-year/lifetime. Serious traffic violations → 60/120/365 days. The penalties are dramatically different.

BAC Thresholds

Critical Exam Fact: The 0.02% threshold is lower than the 0.04% disqualification level, but it triggers an immediate out-of-service order rather than a formal disqualification. Violating an out-of-service order carries its own separate penalties (180 days to 5 years).

Common Pitfalls

Here are the traps that catch unprepared test-takers:

⚠️ Pitfall #1: Mixing Up Property-Carrying and Passenger-Carrying Numbers

The Trap: Applying 11-hour driving limit to passenger-carrying questions, or 10-hour limit to property-carrying.

How to Avoid: Memorize the P-L-U-S mnemonic. Property = 11 driving / 14 window. Passenger = 10 driving / 15 window. The driving limit is lower for passenger; the window is higher.

⚠️ Pitfall #2: 30-Minute Break Timing Misunderstanding

The Trap: Thinking the break is required after 8 hours of driving only, or that it can be taken anytime.

How to Avoid: The break is triggered after 8 cumulative hours of driving and on-duty time since your last qualifying break. It applies to property-carrying drivers only.

⚠️ Pitfall #3: Confusing Major Offenses with Serious Traffic Violations

The Trap: Selecting “speeding” as a major offense, or “DUI” as a serious traffic violation.

How to Avoid: Major offenses = DUI, fleeing the scene, felony use of CMV, driving with revoked CDL, fatal negligence. Everything else (speeding, reckless driving, lane changes, following distance) = serious traffic violations.

⚠️ Pitfall #4: Swapping BAC Thresholds (0.04% vs 0.02%)

The Trap: Saying 0.02% causes disqualification, or 0.04% means out-of-service.

How to Avoid: 0.04% = disqualification (formal, long-term penalty). 0.02% = out-of-service (immediate, temporary removal). Think: lower number = faster consequence (pulled off road immediately at 0.02%).

⚠️ Pitfall #5: Assuming Any 34-Hour Break Counts as a Restart

The Trap: Answering “yes” when a scenario describes a 34-hour break without mentioning 1 AM–5 AM periods.

How to Avoid: The restart must include two periods between 1:00 AM and 5:00 AM home terminal time. No exceptions. Also, only once per 168 hours (7-day period).

⚠️ Pitfall #6: Thinking the Driver Chooses 60-Hour vs 70-Hour Rule

The Trap: Answering “the driver” when asked who determines the applicable weekly limit.

How to Avoid: The carrier (employer) makes this determination based on their operating schedule. The driver simply follows whichever rule the carrier has designated.

⚠️ Pitfall #7: Applying Non-CDL BAC Standards

The Trap: Selecting 0.08% as the disqualification threshold (that’s the non-CDL DUI limit).

How to Avoid: CDL drivers face disqualification at 0.04% — exactly half the standard limit. This applies even when driving a personal vehicle.

⚠️ Pitfall #8: Believing AOBRDs Are Still Valid

The Trap: Selecting “AOBRD” as an acceptable alternative to ELDs.

How to Avoid: The AOBRD grandfather period ended December 16, 2019. All CMVs that require an ELD must now use an ELD — AOBRDs are no longer acceptable.

How This Topic Is Tested

Understanding the question patterns helps you recognize what’s being asked, even before you process the details.

📋 Pattern 1: Numerical Recall — “What is the maximum…?”

Example: “What is the maximum number of hours a property-carrying driver may drive within a 14-hour on-duty period?”

What They’re Testing: Direct recall of HOS limits.

How to Answer: You either know the number or you don’t. Memorize 11-14-30 for property-carrying and 10-15 for passenger-carrying.

Frequency: Most common question type in this domain — expect 1–2 of these.

📋 Pattern 2: Category Identification — “Which of the following is classified as…?”

Example: “Which of the following is classified as a major offense under federal CDL regulations?”

What They’re Testing: Your ability to correctly categorize violations into major offenses vs. serious traffic violations.

How to Answer: Use the D-R-I-V-E mnemonic. If the answer involves DUI, fleeing a crash scene, or committing a felony with a CMV → major offense. If it involves speeding, reckless driving, or lane violations → serious traffic violation.

Frequency: Very common — expect 1 of these.

📋 Pattern 3: Scenario Calculation — “A driver has been on duty for… can they…?”

Example: “A property-carrying driver began their shift at 6:00 AM, drove until 11:30 AM, took a 30-minute break, then drove until 4:00 PM. How many hours of driving time do they have remaining?”

What They’re Testing: Applied HOS calculation — can you track and calculate remaining hours?

How to Answer: Work step-by-step: (1) Calculate total driving hours used, (2) Calculate total on-duty hours used, (3) Apply both the driving-hour limit AND the window limit — the more restrictive one wins.

Frequency: Appears in moderate-difficulty questions — expect 0–1 of these.

📋 Pattern 4: Exception Identification — “Which of the following is exempt from…?”

Example: “Which of the following vehicles is NOT required to be equipped with an Electronic Logging Device?”

What They’re Testing: Knowledge of ELD exemptions and edge cases.

How to Answer: Use the M-A-P-S mnemonic. Look for answers mentioning pre-2000 vehicles, short-haul radius, driveaway-towaway, or agricultural operations.

Frequency: Moderate — expect 0–1 of these.

Key Vocabulary

Red Flag Answers

On the exam, some answer choices are designed to look plausible but are factually wrong. Watch for these red flags:

Exam Strategy: When you see any of these red flags, eliminate that answer choice immediately. The exam often pairs one correct answer with two plausible distractors that contain swapped numbers or mixed-up categories.

Myth-Busters

Let’s clear up common misconceptions about Federal Regulations:

💡 Myth: “HOS rules only apply to long-haul cross-country drivers.”

Reality: HOS rules apply to virtually all CMV operations, including local routes. The only major exception is the short-haul exemption (within 100 air-mile radius, 12-hour shifts). Most drivers — local or long-haul — must comply with full HOS rules.

💡 Myth: “A DUI in my personal car doesn’t affect my CDL.”

Reality: Wrong. A DUI conviction in any vehicle — personal car, motorcycle, anything — triggers CDL disqualification under federal regulations. The major offense provisions apply regardless of what vehicle you were driving.

💡 Myth: “CDL drivers follow the same 0.08% BAC limit as everyone else.”

Reality: CDL holders face disqualification at 0.04% — exactly half the standard 0.08% limit. And you can be placed out-of-service at just 0.02%. These limits apply even when you’re driving your personal vehicle on your day off.

💡 Myth: “If my ELD breaks, I can’t drive until it’s fixed.”

Reality: You CAN continue driving after an ELD malfunction, but with conditions: notify your carrier within 24 hours, switch to paper logs, and continue on paper for up to 8 days while the ELD is being serviced.

💡 Myth: “Once I have my CDL, I’m fully qualified forever.”

Reality: CDL qualification is ongoing. You must maintain a valid Medical Examiner’s Certificate, comply with all HOS rules, and keep your driving record clean. Disqualifications can suspend your CDL at any time.

💡 Myth: “AOBRDs are a valid alternative to ELDs.”

Reality: AOBRDs have been fully phased out since December 2019. Every CMV that requires electronic logs must now use an ELD — AOBRDs are no longer legally acceptable. Some older study materials may still reference them.

Real-World Applications

Understanding these regulations isn’t just about passing the test — these rules govern your daily life as a professional driver.

Scenario 1: Long-Haul Delivery Deadline Pressure
You’re on day 6 of an 8-day cycle with 67 of your 70 available hours used. Your dispatcher wants you to complete a delivery 280 miles away (~4.5 hours). You calculate: 70 – 67 = 3 hours remaining. You can’t legally complete the trip. Real-world skill: knowing how to assert your legal limits professionally and document your availability.

Scenario 2: School Bus Driver Double Shift
A school bus driver operates morning routes (6:00 AM–8:30 AM), then afternoon routes (2:30 PM–4:00 PM). That’s only 4 hours of driving — well within the 10-hour passenger-carrying limit. But if the district adds a field trip from 5:00 PM–7:30 PM, the total jumps to 7 hours. Still legal, but you must track it carefully against your 10-hour driving limit.

Scenario 3: ELD Failure on a Tuesday Afternoon
Your ELD shows a malfunction error at 2 PM. You notify your carrier by phone (documented) at 3 PM — well within the 24-hour window. You pull out your paper log book and begin recording duty status manually. You continue on paper logs for 4 days until your mechanic replaces the ELD. Legal, compliant, and handled correctly.

Study Plan

Here’s a focused 3-phase plan to master this domain:

Phase 1: Core Memorization (45–60 minutes)

Goal: Lock down the key numbers and categories.

1. Memorize 11-14-30 (property-carrying HOS)
2. Memorize 10-15 (passenger-carrying HOS)
3. Memorize 0.04% and 0.02% (BAC thresholds)
4. Memorize D-R-I-V-E (major offenses)
5. Learn the difference between major offenses (1-yr/3-yr/lifetime) and serious traffic violations (60/120/365 days)
6. Review the P-L-U-S and M-A-P-S mnemonics

Phase 2: Application & Comparison (45–60 minutes)

Goal: Apply the rules to scenarios and distinguish between similar categories.

1. Practice comparing property-carrying vs passenger-carrying HOS side-by-side
2. Work through HOS scenario calculation questions
3. Study ELD exemption identification
4. Review disqualification duration tables (1st offense, 2nd offense, HazMat escalation)
5. Practice identifying whether a scenario describes a major offense or serious traffic violation

Phase 3: Pitfall Prevention & Practice (30–45 minutes)

Goal: Eliminate mistakes and confirm readiness.

1. Review all 8 common pitfalls above
2. Study the red flag answers table
3. Take 5–10 practice questions on Federal Regulations
4. Review any questions you get wrong against the strategy document
5. Do a final review of the cheat sheet numbers

Total Time: 2–2.5 hours for comprehensive preparation. 1.5 hours if you’re already somewhat familiar with the material.

Frequently Asked Questions

Q: What is the 30-minute break rule and when is it required?

The 30-minute break is required for property-carrying drivers after they have accumulated 8 or more consecutive hours of driving and/or on-duty time without taking a break of 30 minutes or more (in the sleeper berth or off-duty). The break must be at least 30 minutes long and can be taken off-duty, in the sleeper berth, or using the sleeper berth provision. Passenger-carrying drivers do not have a specific 30-minute break requirement.

Q: Can I use the 34-hour restart more than once a week?

No. The 34-hour restart may only be used once per 168-hour (7-day) period. If you use a restart on Monday, you cannot use another restart until the following Monday. The restart period must also include at least two periods between 1:00 AM and 5:00 AM (home terminal time) and last at least 34 consecutive off-duty hours.

Q: What’s the difference between 60-hour/7-day and 70-hour/8-day rules?

Both are weekly on-duty limits, but the carrier (employer) determines which one applies based on their operating schedule. The 60-hour/7-day rule is for carriers who don’t operate every day. The 70-hour/8-day rule is for carriers that operate 7 days a week. Both can be reset using the 34-hour restart provision. The driver does not choose — the carrier’s designation applies.

Q: What BAC level will get my CDL disqualified?

Operating a CMV (or any vehicle) with a BAC of 0.04% or higher results in CDL disqualification — 1 year for the first offense, 3 years if you hold a HazMat endorsement, and lifetime for a second offense. Additionally, operating a CMV at 0.02% BAC or higher triggers an out-of-service order, meaning you must stop driving immediately and cannot resume until below 0.02%.

Q: Do all commercial vehicles need an ELD?

No. Key ELD exemptions include vehicles manufactured before the year 2000, driveaway-towaway operations (where the ELD can’t be installed on the vehicle being delivered), short-haul drivers operating within 100 air-mile radius with shifts of 12 hours or less who start and end at the same location, and certain agricultural operations within 150 air-mile radius. Check current FMCSA guidelines for the complete exemption list.

Q: What is ELDT and does it apply to me?

Entry-Level Driver Training (ELDT) has been required since February 7, 2022, for anyone applying for a new Class A or Class B CDL, or for Hazardous Materials, Passenger, or School Bus endorsements. Training must be completed through a provider listed on the FMCSA Training Provider Registry. If you already held your CDL or endorsement before this date, ELDT does not apply retroactively to you.

Q: What happens if I get a speeding ticket in my personal car?

A speeding conviction (15+ mph over the limit) in any vehicle counts as a serious traffic violation under CDL regulations. First offense = 60-day CDL disqualification. Second offense within 3 years = 120 days. Third offense within 3 years = 1 year. Your personal driving record directly impacts your CDL privileges.

Q: How long must ELD records be retained?

Motor carriers are required to retain ELD records for a minimum of 6 months. This includes HOS data, ELD malfunction events, and diagnostic information. The data must be available for inspection by law enforcement and FMCSA during roadside inspections and compliance reviews.

Conclusion + Call to Action

Federal Regulations may represent only about 8% of the CDL General Knowledge test, but it’s arguably the most efficient domain to study. The questions are factual, numerical, and highly predictable. With the right approach — memorizing the key numbers (11-14-30, 10-15, 0.04%, 0.02%), understanding the category distinctions (major offenses vs serious traffic violations), and watching for the common traps (mixed-up BAC thresholds, driver vs carrier choice on weekly limits) — you can virtually guarantee a perfect score on every question in this domain.

Your Next Step: Put this knowledge to the test with our Federal Regulations Practice Quiz (Parts 1 & 2), where you’ll encounter real exam-style questions covering HOS rules, ELD requirements, driver qualifications, and disqualification penalties. Each question includes detailed explanations to reinforce what you’ve learned here.

Other Study Guides in This Series:

• CDL Vehicle Inspection & Maintenance Study Guide
• CDL Basic Vehicle Control & Operations Study Guide
• CDL Cargo Management & Securement Study Guide
• CDL Night Driving & Extreme Conditions Study Guide
• CDL Emergency Maneuvers Study Guide

Good luck on your exam — you’ve got this! 🚛

Disclaimer: This study guide is based on federal regulations current as of the publication date. Always verify with the most recent FMCSA regulations and your state’s specific CDL manual for the most up-to-date requirements.