Trucking Safety Rules

The Federal Motor Carrier Safety Regulations (FMCSRs) govern every aspect of commercial trucking. Understanding these rules is essential to understanding what went wrong in your accident.

About the FMCSRs

The Federal Motor Carrier Safety Regulations are a comprehensive set of rules administered by the Federal Motor Carrier Safety Administration (FMCSA). They cover everything from how many hours a driver can work to how cargo must be secured. When these rules are violated, accidents happen. When accidents happen, violations become evidence of negligence. This page provides an overview of the most important regulatory categories. The full regulations are available at FMCSA.dot.gov

Hours of Service (HOS)

49 CFR Part 395
Limits on daily and weekly driving time designed to prevent fatigue-related crashes. Includes the 11-hour driving limit, 14-hour on-duty window, 30-minute break requirement, and 60/70-hour weekly limits.

Key Requirements

  • Maximum 11 hours driving after 10 consecutive hours off duty
  • Cannot drive after the 14th hour following start of on-duty period
  • 30-minute rest break required after 8 cumulative hours of driving
  • 60/70-hour limit in 7/8 consecutive days

Driver Qualifications

49 CFR Part 391

Requirements for who can legally operate a commercial motor vehicle, including CDL requirements, medical certification, background checks, and drug/alcohol testing.

Key Requirements

  • Valid Commercial Driver’s License (CDL) required
  • DOT physical examination every 24 months
  • Pre-employment drug testing mandatory
  • Carriers must investigate 3 years of prior employment

Vehicle Weight Limits

23 CFR Part 658
Federal weight limits designed to protect roads and ensure vehicle stability. Violations dramatically increase stopping distances and crash severity.

Key Requirements

  • 80,000 lbs maximum gross vehicle weight
  • 20,000 lbs maximum single axle weight
  • 34,000 lbs maximum tandem axle weight
  • Bridge formula limits apply to axle spacing
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Vehicle Maintenance

49 CFR Part 396
Requirements for systematic inspection, repair, and maintenance of commercial vehicles. Brake failures, tire blowouts, and lighting defects are all preventable with proper maintenance.

Key Requirements

  • Annual inspection required for all commercial vehicles
  • Drivers must complete pre-trip and post-trip inspections
  • Defects affecting safety must be repaired before vehicle operates
  • Maintenance records must be retained for 1 year

Cargo Securement

49 CFR Part 393
Rules governing how cargo must be loaded, distributed, and secured to prevent shifting, falling, or becoming a hazard. Applies to carriers, drivers, and shippers.

Key Requirements

  • Cargo must be immobilized or secured against movement
  • Specific rules for different cargo types (logs, steel, vehicles, etc.)
  • Minimum number of tie-downs based on cargo length and weight
  • Cargo must be inspected within first 50 miles and periodically thereafter

Drug & Alcohol Testing

49 CFR Part 382
Mandatory testing program for commercial drivers including pre-employment, random, post-accident, reasonable suspicion, and return-to-duty testing.

Key Requirements

  • Pre-employment testing required before first drive
  • Random testing: minimum 50% of drivers annually for drugs, 10% for alcohol
  • Post-accident testing required when fatality, injury, or vehicle tow occurs
  • Positive test results must be reported to FMCSA Drug & Alcohol Clearinghouse

Was a Safety Rule Violated in Your Accident?

Understanding which FMCSR regulations were broken is central to building a strong truck accident case. Bryan Green can review the facts of your accident and identify the specific violations that apply.

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