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Complete CDL Study Guide

Master all 7 sections of the CDL general knowledge test

📚 How to Use This Study Guide

  1. Read each section carefully
  2. Take notes on key numbers
  3. Test yourself with our practice test
  4. Review weak areas

Section 1: Vehicle Inspection

Pre-Trip Inspection

Perform thorough pre-trip inspection before every trip.

Seven-Step Method:

  1. Vehicle Overview - Check for damage, leaks
  2. Engine Compartment - Oil, coolant, belts
  3. Start Engine - Check gauges, controls
  4. Turn Off Engine - Check lights
  5. Walk-Around - Tires, brakes, suspension
  6. Signal Lights - All functioning
  7. Start Engine - Check brake system

Critical Items:

  • Tire tread: 4/32" front, 2/32" others
  • Air brakes: 100-125 psi
  • All lights working
  • Mirrors clean and adjusted

Section 2: Basic Control

Shifting and Speed

Shift at recommended RPM. Downshift before hills.

Backing Safely:

  • Get out and look (GOAL)
  • Back slowly
  • Use mirrors constantly
  • Sound horn
  • Back to driver's side when possible

Section 3: Braking Systems

Air Brake System

Critical Numbers:

  • Normal pressure: 100-125 psi
  • Low air warning: Before 60 psi
  • Emergency brakes: Below 20-45 psi
  • Pressure buildup: 85 to 100 psi in 45 seconds
  • Air loss: Max 3 psi/min (single) or 4 psi (combination)

Section 4: Safe Driving

Following Distance

One second per 10 feet of vehicle length under 40 mph.

  • 40-foot vehicle = 4 seconds minimum
  • Add 1 second above 40 mph
  • Add 1 second in bad weather

Night Driving:

  • Clean headlights and windshield
  • Reduce speed
  • Don't overdrive headlights
  • Watch for animals

Section 5: Cargo Securement

Weight Limits

  • Maximum gross: 80,000 lbs Interstate
  • Steer axle: 12,000 lbs max
  • Single axle: 20,000 lbs max
  • Tandem axle: 34,000 lbs max

Securement Rules:

  • Minimum 2 tie-downs up to 10 feet
  • Add 1 per additional 10 feet
  • Check within 50 miles of start
  • Re-check every 3 hours or 150 miles

Section 6: Hazardous Conditions

Weather Conditions

Rain:

  • Reduce speed by 1/3 on wet roads
  • Reduce by 1/2 in heavy rain

Ice and Snow:

  • Black ice at 32°F
  • Bridges freeze first
  • Reduce speed 50% or more
  • Don't use engine brake on ice

Fog:

  • Use low-beam headlights
  • Never use high beams
  • Pull over if visibility too poor

Section 7: Rules and Regulations

Hours of Service

  • 11-Hour Limit: Max 11 hours driving after 10 hours off
  • 14-Hour Limit: Can't drive beyond 14th hour on duty
  • Rest Break: 30-minute break after 8 hours driving
  • 60/70-Hour Limit: Max 60/70 hours in 7/8 days

Required Documents:

  • Valid CDL license
  • Medical certificate
  • Vehicle registration
  • Proof of insurance
  • Logbook/ELD records

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