CDL General Knowledge Test Guide

What every manual says

Taken in turn from every part of the manual this test covers: the CDL rules themselves, the vehicle inspection, control and signaling, speed and space, night driving and railroad crossings, emergencies, hazmat basics and cargo.

1. Inspecting Cargo

   Inspect the cargo and securing devices within the first 50 miles of a trip, then re-check as often as needed: after 3 hours or 150 miles of driving and after every break. Weight, securement, load-covering and route rules vary from place to place, so know the rules where you drive.

   CA · p. 3-1

2. Legal Weight Limits

   Keep weights within legal limits for GVWR, GCWR and axle weights.

   CA · p. 3-2

3. Don't Be Top-heavy

   A high center of gravity (cargo piled high or heavy cargo on top) makes tipping over more likely, especially in curves or when swerving; keep the cargo as low as possible, with the heaviest parts under the lightest.

   CA · p. 3-2

4. Cargo Tie-down

   On flatbeds or trailers without sides cargo must be tied down, and in closed vans tie-downs can keep cargo from shifting.

   CA · p. 3-3

5. Accelerating

   Don’t roll back when you start, or you may hit someone behind you: with a manual transmission, partly engage the clutch before taking your right foot off the brake.

   CA · p. 2-9

6. Backing Safely

   Backing is always dangerous because you cannot see everything behind you, so avoid it when you can and park so you can pull forward when you leave.

   CA · p. 2-10

7. Backing Safely

   Back as slowly as possible in the lowest reverse gear, so you can correct steering errors more easily and stop quickly if needed; check the outside mirrors on both sides often, and get out to check your path if you are unsure.

   CA · p. 2-10

8. Backing Safely

   Use a helper whenever you can, because of blind spots; the helper stands near the back where you can see them, and before backing you agree on hand signals, including one for "stop".

   CA · p. 2-10

9. Stopping Distance

   Heavier vehicles make the brakes work harder and absorb more heat, but the brakes, tires, springs and shocks of heavy vehicles work best when fully loaded; empty trucks need greater stopping distances because they have less traction.

   CA · p. 2-16

10. Matching Speed to the Road Surface

    Signs of slippery roads: shaded areas stay icy after open areas melt; bridges freeze before the road (be careful near 32°F); slightly melting, wet ice is more slippery than dry ice; and the road is very slippery just after rain begins, as water mixes with oil until more rain washes it away.

    CA · p. 2-17

11. Speed and Curves

    Taking a curve too fast can make the tires lose traction so you skid off the road, or keep traction so the vehicle rolls over.

    CA · p. 2-17

12. Watch Out for Other Distracted Drivers

    Signs of a distracted driver include drifting over lane lines or within the lane, inconsistent speeds, being busy with maps, food, cigarettes or phones, and talking with passengers.

    CA · p. 2-27

13. What You Should Do When Confronted by an Aggressive Driver

    When confronted by an aggressive driver: first get out of their way.

    CA · p. 2-28

14. Driver Factors

    Bright light can blind drivers for a short time, and it can take several seconds to recover; even two seconds of glare blindness is dangerous, since at 55 mph you travel more than half a football field.

    CA · p. 2-28

15. Roadway Factors

    Night roads are often poorly lit, so you depend on your headlights, and unlit road users (pedestrians, joggers, bicyclists, animals) are hard to see.

    CA · p. 2-30

16. Driving Procedures

    Never race a train to a crossing, since its speed is very hard to judge; reduce speed so you can see trains in any direction and can stop short of the tracks if needed.

    CA · p. 2-36

17. Stopping Safely at Railroad- highway Crossings

    A full stop at a crossing is required when the cargo makes it mandatory under state or federal rules or when the law otherwise requires it; when stopping, check traffic behind you and stop gradually, use a pullout lane if there is one, and turn on your four-way flashers.

    CA · p. 2-36

18. Special Situations

    Don’t expect to hear a train (horns may not sound at some crossings, and cab noise can hide them) and don’t rely only on signals, gates or flaggers.

    CA · p. 2-36

19. Select the Right Gear before Starting Down the Grade

    Shift to a low gear before starting down a grade; don’t try to downshift once speed has built up, since you may not get into a lower gear (or any gear) and all engine braking is lost.

    CA · p. 2-37

20. Fire Fighting

    A B:C extinguisher is for electrical fires and burning liquids.

    CA · p. 2-45

21. Lists of Regulated Products

    Identification numbers are four-digit codes, preceded by "NA" or "UN", that first responders use to identify hazardous materials.

    CA · p. 2-48

22. Lists of Regulated Products

    Not every vehicle carrying hazardous materials needs placards.

    CA · p. 2-49

23. Alcohol, drugs, illness and hazmat basics

    If you are stopped driving a vehicle that needs placards without the hazmat endorsement, you will be cited and not allowed to drive it on, which costs time and money.

    CA · p. 2-49

24. Vehicle Inspection

    Safety, for yourself and other road users, is the most important reason to inspect your vehicle; a defect found early can also prevent a costly breakdown or a crash.

    CA · p. 2-1

25. Vehicle Inspection

    Re-grooved, recapped or retreaded tires are not allowed on the front wheels of a bus.

    CA · p. 2-2

26. Vehicle Inspection

    Wheel and rim problems include damaged rims, missing clamps, spacers, studs or lugs, mismatched, bent or cracked lock rings, and wheels or rims with welding repairs, which are not safe.

    CA · p. 2-2

27. Vehicle Inspection

    Steering wheel play of more than 10 degrees (about 2 inches at the rim of a 20-inch wheel) can make steering hard; also look for missing nuts, bolts or cotter keys, bent or loose steering parts, and power steering hose, pump or fluid problems.

    CA · p. 2-2

28. Introduction

    A vehicle of any size needs a CDL when its load requires hazardous materials placards.

    CA · p. 1-1

29. CDL Disqualifications

    It is illegal to drive a CMV with a blood alcohol concentration of .04% or more.

    CA · p. 1-14

30. CDL Disqualifications

    If one of the major offenses happens while driving a CMV placarded for hazardous materials, the CDL is lost for at least three years.

    CA · p. 1-14

How the General Knowledge test differs by state

49 of 50 states give it with 50 questions and 40 to pass. These states differ:

• Illinois30 questions, 24 to pass

Every state's manual: General Knowledge

Each links its general knowledge practice test.

• AlabamaSections 1–3 · p. 11–69
• AlaskaSections 1–3 · p. 5–73
• ArizonaSections 1–3 · p. 6–70
• ArkansasSections 1–3 · p. 7–66
• CaliforniaSections 1–3 · p. 3–93
• ColoradoSections 1–3 · p. 6–58
• ConnecticutSections 1–3 · p. 6–67
• DelawareSections 1–3 · p. 3–73
• FloridaSections 1–3 · p. 2–74
• GeorgiaSections 1–3 · p. 8–129
• HawaiiSections 1–3 · p. 4–76
• IdahoSections 1–3 · p. 10–68
• IllinoisSections 1–15 · p. 2–172
• IndianaSections 1–3 · p. 2–67
• IowaSections 1–3 · p. 12–71
• KansasSections 1–3 · p. 7–66
• KentuckySections 1–3 · p. 6–76
• LouisianaSections 1–3 · p. 22–87
• MaineSections 1–3 · p. 4–69
• MarylandSections 1–3 · p. 4–136
• MassachusettsSections 1–3 · p. 3–92
• MichiganSections 1–3 · p. 9–79
• MinnesotaSections 1–3 · p. 5–113
• MississippiSections 1–3 · p. 7–66
• MissouriSections 1–14 · p. 5–169
• MontanaSections 1–3 · p. 2–74
• NebraskaSections 1–3 · p. 5–78
• NevadaSections 1–3 · p. 6–74
• New HampshireSections 1–3 · p. 7–66
• New JerseySections 1–3 · p. 7–66
• New MexicoSections 1–3 · p. 5–69
• New YorkSections 1–3 · p. 5–80
• North CarolinaSections 1–3 · p. 5–71
• North DakotaSections 1–3 · p. 7–72
• OhioSections 1–3 · p. 7–64
• OklahomaSections 1–3 · p. 7–66
• OregonSections 1–3 · p. 7–69
• PennsylvaniaSections 1–3 · p. 14–86
• Rhode IslandSections 1–3 · p. 3–64
• South CarolinaSections 1–3 · p. 5–81
• South DakotaSections 1–3 · p. 12–89
• TennesseeSections 1–3 · p. 9–71
• TexasSections 1–3 · p. 16–76
• UtahSections 1–3 · p. 8–71
• VermontSections 1–3 · p. 3–79
• VirginiaSections 1–3 · p. 1–66
• WashingtonSections 1–3 · p. 9–74
• West VirginiaSections 1–3 · p. 6–104
• WisconsinSections 1–3 · p. 6–101
• WyomingSections 1–3 · p. 5–66