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OR CDL General Knowledge study materials
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OR CDL General Knowledge: General CDL Knowledge (Oregon CDL Manual Core)

OR CDL General Knowledge · Work through your exam, one topic at a time.

All guide sections

General CDL Knowledge (Oregon CDL Manual Core)

General CDL Knowledge is the core section of the Oregon Commercial Driver Manual and the first written test for most Oregon CDL applicants. It tests whether you can operate a commercial motor vehicle safely: pre-trip inspection, basic control, shifting, backing, seeing and communicating, speed and space management, hazard recognition, and accident procedures. Oregon applies the federal CDL standards and adds its own basic speed rule.

Core rules

  • Pre-trip inspection: Know the inspection sequence and what a defect looks like. You must be satisfied the vehicle is safe before you drive.
  • Basic control: Start and stop smoothly, steer without overcorrecting, and select the right gear before a curve or downgrade.
  • Shifting: Know your pattern and ranges. Do not coast in neutral and do not ride the clutch.
  • Seeing and communicating: Aim high, check mirrors, signal early, and make eye contact when possible.
  • Speed and space: Use Oregon's basic speed rule - a speed reasonable and prudent for conditions, not just the posted maximum. Keep a following gap that fits your length and speed.
  • Hazards and emergencies: Scan ahead, identify an out, and act early. Brake before a curve, not in it.
  • Accident procedures: Protect the scene, notify authorities, and exchange information.

Worked example

Your combination is 60 feet long and you are following another truck at 55 mph. The manual's rule is one second per 10 feet below 40 mph, plus one second above 40 mph. Six seconds for length plus one equals a seven-second gap. A three-second passenger-car gap is too short: at 55 mph your total stopping distance can exceed 300 feet, and the truck ahead blocks your view of hazards.

Traps that cost marks

Do not treat the posted speed as a target; Oregon's basic speed rule can require a lower speed. Do not use a car following distance. Do not assume a green light is safe - a stale green means prepare to stop. Do not rely on mirrors alone before backing; get out and check. Do not enter a bridge or overpass without checking height and weight limits.