CDL weak-area practice

CDL General Knowledge Test 1

Use this set after reading the CDL general knowledge outline or when you want a broad check of safe-driving, inspection, cargo, and road-decision topics.

Study the weak area

What to understand before you answer.

This is a mixed CDL practice set. It is useful for finding weak areas before moving into focused drills.

01

Read each question as a real commercial driving decision.

02

Watch for weather, visibility, speed, space, inspection, and cargo clues.

03

Use the explanations after review to decide which focused topic to practice next.

Before the questions

How to improve this score.

  1. Answer every question.
  2. Review the score report and missed explanations.
  3. Open the recommended weak-area drill if one appears.
  4. Retake a mixed set after focused practice.

Common traps to watch for

Backing without a helper or failing to stop when visibility is uncertain.

When this pattern appears in a missed answer, review the explanation before trying another set.

Driving at passenger-car speeds without accounting for weight, space, weather, or grade.

When this pattern appears in a missed answer, review the explanation before trying another set.

Assuming cargo safety is only the shipper or dispatcher responsibility.

When this pattern appears in a missed answer, review the explanation before trying another set.

Memorizing a walk-around order without understanding which defects make the vehicle unsafe.

When this pattern appears in a missed answer, review the explanation before trying another set.

Memorizing rules without applying them to driving scenarios.

When this pattern appears in a missed answer, review the explanation before trying another set.

Practice questions

CDL General Knowledge Test 1 Quiz

Answered 0 / 120
Question 1

When backing a commercial vehicle, which of the following is the most important safety rule?

Question 2

How far ahead should you be looking while driving a commercial vehicle at highway speeds?

Question 3

You are driving a heavily loaded vehicle on a steep downgrade. What is the most important factor in determining your safe speed?

Question 4

What is the minimum tread depth required for the front steering tires of a commercial vehicle?

Question 5

When is it appropriate to use your high beams?

Question 6

Which of the following statements about drinking alcohol and driving is true?

Question 7

What is 'hydroplaning'?

Question 8

If you experience a tire blowout while driving at highway speeds, what is the FIRST thing you should do?

Question 9

How often should you check your cargo while on the road?

Question 10

What is the purpose of a pre-trip inspection?

Question 11

Which type of fire extinguisher should be used on an electrical fire?

Question 12

Why should you avoid using the engine brake (Jake brake) on wet or icy roads?

Question 13

What is the recommended following distance for a heavy vehicle traveling at 55 mph in ideal conditions?

Question 14

What does a broken exhaust system pose the greatest risk of?

Question 15

If your vehicle catches fire while driving, what should you do first?

Question 16

Which of these is a sign of distracted driving?

Question 17

What should you do if you are being tailgated?

Question 18

When approaching a curve, what is the best way to handle your speed?

Question 19

What is the most common cause of serious vehicle skids?

Question 20

What must you do when placing warning devices (triangles) on a two-lane road with traffic in both directions?

Question 21

When driving a commercial vehicle, how should you adjust your speed for driving at night?

Question 22

What is the most important reason for inspecting your vehicle?

Question 23

If you must pull over to the shoulder on a highway, how quickly must you place your warning devices?

Question 24

What should you do if your vehicle begins to hydroplane?

Question 25

Which of these statements about managing space is true?

Question 26

What is black ice?

Question 27

When should you check your mirrors while driving?

Question 28

What is the primary cause of fatal crashes involving commercial vehicles?

Question 29

If you are driving a 60-foot truck at 50 mph, what is the minimum following distance you should maintain?

Question 30

What should you do if an aggressive driver is harassing you?

Question 31

Which of these fires can you safely use water to extinguish?

Question 32

What happens if the drive wheels lose traction and spin?

Question 33

How does cargo weight affect the height of your vehicle's center of gravity?

Question 34

What is the best way to use the brake pedal on a steep downgrade?

Question 35

Why do empty trucks have longer stopping distances than loaded trucks?

Question 36

When backing, why should you back toward the driver's side whenever possible?

Question 37

What does it mean if a vehicle has a 'slow-moving vehicle' symbol?

Question 38

What should you do before driving in the mountains?

Question 39

Which of these is NOT a good rule to follow when caring for an injured person at a crash scene?

Question 40

How can you tell if the road is becoming slippery due to dropping temperatures?

Question 41

Why is it important to shift gears correctly?

Question 42

What should you do if your headlights fail while driving at night?

Question 43

When exiting a highway, when should you start slowing down?

Question 44

What is the primary danger of driving through deep puddles of water?

Question 45

How do you dry wet brakes after driving through deep water?

Question 46

Which of these is true about proper mirror adjustment?

Question 47

What is a 'pull-up' when backing a commercial vehicle?

Question 48

What is the danger of a loose tie-down on your cargo?

Question 49

How often should you inspect your tires during a trip in very hot weather?

Question 50

What should you do if your steering feels heavy or the vehicle pulls to one side?

Question 51

You are approaching a railroad crossing in a heavy commercial vehicle. What is the safest general habit?

Question 52

Why should you avoid shifting gears while crossing railroad tracks?

Question 53

A long downgrade is ahead. What should you do before starting down the grade?

Question 54

What is the safest reason to use an escape ramp?

Question 55

You are driving through fog. Which adjustment is safest?

Question 56

What should you do if you become drowsy while driving?

Question 57

An aggressive driver cuts in front of you and slows down. What is the safest response?

Question 58

Which action is a clear example of distracted driving?

Question 59

Why is proper mirror adjustment part of a safe pre-trip check?

Question 60

When should you signal before changing lanes?

Question 61

What is the safest reason to tap your brake pedal lightly before slowing on a highway?

Question 62

You need to back into a tight area and cannot see the rear of the vehicle clearly. What should you do?

Question 63

Why should you avoid backing whenever possible?

Question 64

Your vehicle drifts toward the shoulder on a narrow road. What is the safest immediate priority?

Question 65

What should you do if your brakes fail on a downgrade and an escape ramp is available?

Question 66

Why is it dangerous to swing wide to the left before making a right turn?

Question 67

When should you use your horn?

Question 68

What is the safest way to handle a curve in a heavy vehicle?

Question 69

Why does a commercial vehicle need more following distance than a passenger car?

Question 70

What should you do if you are forced to stop on the shoulder because of a breakdown?

Question 71

What is the main purpose of reflective warning triangles after a roadside stop?

Question 72

A load seems to have shifted after a hard stop. What should you do before continuing?

Question 73

Why should cargo weight be balanced?

Question 74

What does it usually mean if steering feels loose during a pre-trip check?

Question 75

Why should loose or missing lug nuts be treated seriously?

Question 76

What should you do if a low bridge clearance is posted ahead and you are not sure your vehicle can clear it?

Question 77

What should you do before driving under an overpass with snow or ice on the road?

Question 78

What is the safest way to recover from hydroplaning?

Question 79

Which answer best describes safe communication with other road users?

Question 80

What should you do if a vehicle is tailgating your commercial vehicle?

Question 81

Which pre-trip defect should stop you from driving until it is corrected?

Question 82

Why should you keep both hands on the steering wheel during a tire blowout?

Question 83

You are entering a work zone with narrow lanes in a large commercial vehicle. What is the safest adjustment?

Question 84

What should you do before making a lane change in a commercial vehicle?

Question 85

Why should you look far enough ahead while driving a heavy vehicle?

Question 86

You are turning right in a long vehicle. What is the safest way to manage the turn?

Question 87

What is the safest approach when traffic ahead suddenly slows?

Question 88

Why should a CDL driver avoid driving beside another vehicle for a long time?

Question 89

What should you do if another driver is in your blind spot?

Question 90

A vehicle ahead splashes water across your windshield. What is the safest response?

Question 91

Why should you slow before entering a curve instead of braking hard inside it?

Question 92

What should you do if your vehicle begins to skid?

Question 93

Why should cargo be secured even on a short trip?

Question 94

What can happen if cargo weight is too far to one side?

Question 95

Which action is safest if you are unsure whether your cargo is still secure after a rough road segment?

Question 96

Why should you avoid overloading a vehicle?

Question 97

A tire fails while you are driving. What should you avoid?

Question 98

What should you do if an oncoming vehicle drifts into your lane?

Question 99

Why should you keep extra space above your vehicle in mind?

Question 100

What is the safest response if your route includes a low-clearance bridge you did not expect?

Question 101

Why does wet pavement require more following distance?

Question 102

You are driving at night and cannot see far enough ahead to stop safely. What should you do?

Question 103

Why should you avoid using cruise control on slippery roads?

Question 104

What should you do if you see a hazard in the road ahead?

Question 105

Which driver condition should stop you from beginning a trip?

Question 106

What should you do after passing a vehicle before returning to the right lane?

Question 107

Why should you be cautious when driving empty or lightly loaded?

Question 108

What should you do if you are unsure whether a road is icy?

Question 109

What is the safest reason to check mirrors after completing a turn?

Question 110

Why should a driver know the vehicle's length before entering traffic or crossing intersections?

Question 111

Why can cargo loaded too high increase rollover risk?

Question 112

A driver notices a tiedown is loose during a trip. What is the safest response?

Question 113

What is one danger of cargo that shifts suddenly during a turn?

Question 114

Which cargo issue should be corrected before driving?

Question 115

Why should weight distribution matter to a CDL driver?

Question 116

A sealed trailer feels unstable after loading. What should a driver avoid doing?

Question 117

When should cargo securement be checked?

Question 118

A cargo question asks who is responsible for making sure the load is safe to transport. What is the best CDL study answer?

Question 119

Why can liquid cargo be especially challenging even when the vehicle is not overloaded?

Question 120

If cargo falls from a commercial vehicle, what is the main safety concern?

Study before retesting

Review before you try again.