DOT Rules and Regulations for Truck Drivers: CDL, Hours, and Penalties

The U.S. Department of Transportation regulates commercial truck drivers through the Federal Motor Carrier Safety Administration, and the DOT rules and regulations for truck drivers cover five things that matter on the road every day: who is allowed to hold a commercial license, whether the driver is medically fit, how many hours the driver can work, whether the driver is free of drugs and alcohol, and whether the truck itself is safe to operate. Miss any one of them and you can be placed out of service on the spot.

The rules below apply to anyone driving a commercial motor vehicle in interstate commerce. That generally means a vehicle over 10,001 pounds, one designed to carry 16 or more passengers (or 9 or more for compensation), or any vehicle hauling placarded hazardous materials. Most states apply the same standards to intrastate driving, but the age rules and a few procedural details can differ inside a single state.

Who Needs a CDL and What Class

Anyone driving a commercial motor vehicle needs a Commercial Driver’s License issued under 49 CFR Part 383. The class depends on what you drive:

You must be at least 21 to drive a commercial vehicle in interstate commerce.2Federal Motor Carrier Safety Administration. What Is the Age Requirement for Operating a CMV in Interstate Commerce Most states let drivers 18 to 20 hold a CDL for intrastate work only. The FMCSA also runs the Safe Driver Apprenticeship Pilot Program, which allows carriers to train 18-, 19-, and 20-year-old drivers for interstate work under specific conditions, though its future depends on congressional reauthorization.3Federal Register. Safe Driver Apprenticeship Pilot Program To Allow Persons Ages 18, 19, and 20 To Operate Commercial Motor Vehicles in Interstate Commerce

Certain cargo and vehicle types require endorsements on top of the base license. Hazardous materials, double or triple trailers, tank vehicles, passenger transport, and school buses each carry their own written or skills test. The hazmat endorsement additionally requires a TSA security threat assessment.1eCFR. 49 CFR Part 383 – Commercial Driver’s License Standards, Requirements and Penalties

Entry-Level Driver Training

Since February 2022, first-time CDL applicants and drivers upgrading their class or adding a passenger, school bus, or hazmat endorsement must complete Entry-Level Driver Training through a provider listed on the FMCSA’s Training Provider Registry. Training has two required parts: theory instruction (classroom or online) and behind-the-wheel work split between a closed course and public roads. There is no minimum number of hours; you advance when you demonstrate competence.4eCFR. 49 CFR Part 380 Subpart F – Entry-Level Driver Training You cannot take the CDL skills test until the provider certifies your completion in the registry.

The DOT Physical and Medical Card

A CDL alone doesn’t put you behind the wheel legally. Under 49 CFR Part 391, you must pass a physical exam and carry a valid Medical Examiner’s Certificate, and the exam has to be done by a provider on the FMCSA’s National Registry of Certified Medical Examiners.5eCFR. 49 CFR Part 391 Subpart E – Physical Qualifications and Examinations

The exam checks for minimum distant visual acuity of 20/40 in each eye (with or without correction), the ability to perceive a forced whisper at five feet or better, and conditions like high blood pressure or diabetes that could cause sudden incapacitation. A standard certificate is good for up to two years, but the examiner can issue a shorter one when a condition needs more frequent monitoring, such as controlled hypertension.5eCFR. 49 CFR Part 391 Subpart E – Physical Qualifications and Examinations

Drivers who don’t meet the standard vision threshold may still qualify under the alternative vision standard in 49 CFR 391.44, which requires evaluation and documentation by a vision specialist. A similar path exists for drivers with insulin-treated diabetes, who must complete a specific assessment form and show stable management of the condition.6Federal Motor Carrier Safety Administration. Medical Examiners Handbook After every exam, you have to provide a copy of the certificate to your state licensing agency.

Hours of Service

The hours-of-service rules in 49 CFR Part 395 set strict limits on how long you can drive and work. For property-carrying vehicles, five numbers do most of the work:

Adverse Conditions and Short-Haul Exceptions

Two exceptions come up constantly. The adverse driving conditions exception adds 2 hours to both the driving limit and the 14-hour window when you hit unexpected weather, a road closure, or traffic you couldn’t have predicted before the trip started. Foreseeable problems like seasonal construction or normal rush-hour traffic don’t qualify.

The short-haul exception exempts you from keeping detailed logs if you operate within a 150-air-mile radius of your normal work reporting location and return there within 14 consecutive hours.8Federal Motor Carrier Safety Administration. Summary of Hours of Service Regulations Local delivery and construction fleets rely on it heavily.

Electronic Logging Devices

Hours are tracked by Electronic Logging Devices wired into the truck’s engine, which automatically record driving time. ELDs replaced paper logs to end the fudging that was common under the old system. At a roadside inspection you must be able to produce ELD records on demand. If the device is malfunctioning or missing, the inspector will place you out of service for at least 10 hours and cite the carrier for a recordkeeping violation, which also feeds into the carrier’s safety scores.9Federal Motor Carrier Safety Administration. ELD FAQ16 – Electronic Logging Devices and Hours of Service

Drug and Alcohol Testing

If you perform safety-sensitive functions, you’re subject to drug and alcohol testing under 49 CFR Part 382 and Part 40. Employers must test new hires before they drive, run random tests through the year, and order testing after certain accidents or when a supervisor observes signs of impairment.10eCFR. 49 CFR Part 382 – Controlled Substances and Alcohol Use and Testing The DOT panel screens for five substance classes: marijuana, cocaine, amphetamines, opioids, and phencyclidine.11eCFR. 49 CFR Part 40 – Procedures for Transportation Workplace Drug and Alcohol Testing Programs

Every violation is reported to the FMCSA Drug and Alcohol Clearinghouse, the centralized database employers must query before hiring any CDL driver and at least once a year for every CDL driver on their payroll.12Federal Motor Carrier Safety Administration. Clearinghouse Annual Queries

Return-to-Duty After a Positive Test

Testing positive or refusing a test doesn’t just cost you a job. The Clearinghouse flags the violation, and you can’t perform any safety-sensitive work again until you complete a structured return-to-duty process: an evaluation by a DOT-qualified Substance Abuse Professional, whatever education or treatment the SAP recommends, a follow-up evaluation confirming compliance, and a directly observed return-to-duty test that comes back negative. Any employer who hires you during the prescribed follow-up period must also complete the SAP’s follow-up testing plan.13Federal Motor Carrier Safety Administration. The Return-to-Duty Process

Vehicle Inspections You’re Responsible For

Under 49 CFR Part 396, drivers do daily pre-trip and post-trip inspections and record them on a Driver Vehicle Inspection Report. If you find a safety-related defect, the truck can’t be driven until it’s fixed.14eCFR. 49 CFR Part 396 – Inspection, Repair, and Maintenance

Beyond daily checks, every commercial vehicle must pass a comprehensive annual inspection covering all components in the federal minimum inspection standards. Proof of that inspection, whether the full report or a sticker showing the inspection date, inspector information, and vehicle ID, has to stay on the truck at all times.15eCFR. 49 CFR 396.17 – Periodic Inspection The person who signs the annual inspection must have at least a year of combined training or experience in commercial vehicle maintenance or inspection.16eCFR. 49 CFR 396.19 – Inspector Qualifications

Penalties Drivers Face

The FMCSA adjusts penalty amounts annually for inflation, and the 2025 figures for drivers are higher than many realize:

On top of the fines, your record follows you. Violations feed the carrier’s scores under the FMCSA’s Compliance, Safety, Accountability program across categories including unsafe driving, HOS compliance, driver fitness, controlled substances, and vehicle maintenance. Poor scores can trigger warning letters, on-site audits, or in the worst case an unsatisfactory safety rating that shuts operations down.18Federal Motor Carrier Safety Administration. CSA Compliance, Safety, Accountability For an individual driver, a positive drug test or refusal in the Clearinghouse is the record that’s hardest to walk away from, because no future employer can put you behind the wheel until the return-to-duty process is complete.