Federal Motor Carrier Safety Regulations

The Federal Motor Carrier Safety Regulations are the federal rulebook for commercial motor vehicles operating in interstate commerce. They apply to commercial trucks, buses, and other large vehicles, and they reach the motor carrier, the driver, the maintenance shop, and the shipper. When a truck crash causes serious injury, each part of the regulations offers a separate line of investigation into what the carrier and driver were required to do.

Core Parts of 49 CFR in Truck Crash Cases

Seven parts of Title 49 of the Code of Federal Regulations come up most often in a commercial truck crash case:

A crash investigation checks the carrier’s compliance with every part that touches the crash, then obtains the documents that show whether the carrier complied.

Hours of Service Limits

Federal hours of service rules cap how long a driver can operate before mandatory rest, because fatigue contributes to large truck crashes. The current limits for property-carrying drivers, according to the FMCSA Hours of Service summary, are:

• An 11-hour driving limit after 10 consecutive hours off duty.
• A 14-hour on-duty window before another 10-hour off-duty break.
• A 30-minute break after 8 cumulative hours of driving.
• A limit of 60 hours on duty in any 7 consecutive days, or 70 hours in 8 consecutive days.

Electronic Logging Device Records

Electronic logging devices record a driver’s duty status while the truck operates. Under 49 CFR 395.22, a motor carrier must retain a backup copy of ELD records for six months. A preservation letter sent early in a case requires the carrier to keep those records before they can be overwritten, edited, or reported missing.

Driver Qualification Files

A carrier must build and maintain a driver qualification file before a driver operates a commercial vehicle in interstate commerce. The file holds the driver’s application, road test, medical certification, prior employer checks, and motor vehicle record, on paper or electronically. Under 49 CFR Part 391, the file must include:

• The driver’s employment application.
• Three years of safety performance history from prior employers.
• A current medical examiner’s certificate.
• An annual review of the driver’s driving record.
• A road test certificate or an accepted equivalent.

Missing or incomplete files are common with owner-operators, independent contractors, and recently hired drivers. When a carrier puts an unqualified driver on the road and a crash follows, a driver qualification violation can support a negligent hiring claim against the carrier.

Vehicle Maintenance Records

Every safety-critical component on a commercial truck, including brakes, tires, suspension, lighting, steering, and coupling devices, has a federal inspection standard. Under 49 CFR Part 396, carriers must systematically inspect, repair, and maintain every vehicle they operate, and drivers must complete a driver vehicle inspection report when defects are found.

Annual inspection records must be kept for 14 months, and roadside inspection reports for 12 months. Those records show whether a carrier kept its fleet in repair or deferred maintenance to keep trucks on the road. When a crash involves a jackknife, a runaway on a downgrade, or a failure to stop in traffic, Part 396 records are among the first to request.

Drug and Alcohol Testing Rules

Every CDL holder operating a commercial motor vehicle in interstate commerce is subject to federal drug and alcohol testing. Under 49 CFR Part 382, carriers must test at six points:

• Pre-employment.
• Random selection.
• Reasonable suspicion.
• Post-accident, under defined thresholds.
• Return to duty.
• Follow-up after a violation.

After a qualifying crash, 49 CFR 382.303 requires an alcohol test within 8 hours and a controlled substances test within 32 hours. A carrier’s failure to test, failure to document, or failure to remove a driver with a positive result from safety-sensitive work is direct evidence of regulatory noncompliance.

Commercial Driver’s License Standards

A commercial driver’s license carries federal testing and endorsement requirements beyond a regular license. 49 CFR Part 383 sets minimum standards for CDL knowledge tests, skills tests, and endorsements for hazardous materials, passenger vehicles, school buses, tank vehicles, and double or triple trailers.

A driver without the proper endorsement for the vehicle or cargo is operating outside federal qualifications. Investigators check endorsements early because a mismatch points to negligent assignment by the carrier.

Regulation Violations as Crash Evidence

A safety rule violation that causes a crash can establish the carrier’s or driver’s negligence. The regulations set the baseline for interstate motor carriers, and many states adopt the same safety rules for intrastate commercial vehicles. Enforcement records, inspection violations, and out-of-service orders become part of a carrier’s compliance history. State law may treat a violation as evidence of negligence or as negligence per se, so the questions are which rule was broken, who broke it, and whether the violation caused the collision.

Carrier Records To Obtain Quickly

• Electronic logging device records of duty status for the days before the crash.
• The driver’s complete qualification file.
• Pre-trip and post-trip inspection reports.
• Vehicle maintenance records.
• Drug and alcohol testing records, including post-accident results.
• Driver training records and prior crash history.
• Dashcam, in-cab video, and telematics data.

Large Truck Crash Deaths

Large truck crashes kill passenger vehicle occupants far more often than truck occupants. Heavy trucks can weigh 20 to 30 times as much as passenger cars, according to the Insurance Institute for Highway Safety, which also reports that 5,340 people died in large truck crashes in 2024.