CDL General Knowledge Practice Test 3 — Questions and Answers
Question 1: Which of the following is NOT a part of the steering system?
- Main spring (Correct answer)
- Hydraulic fluid reservoir
- Tie rod
- Steering knuckle
Correct answer: Main spring
The steering system in a commercial vehicle is responsible for directing the wheels and includes components like the hydraulic fluid reservoir, tie rods, and steering knuckles. These parts work together to translate the driver's input into wheel movement. A main spring, however, is a component of the suspension system, designed to absorb shocks and support the vehicle's weight, and is not directly involved in the steering mechanism.
Question 2: When backing, what is the best method to use to avoid blind spots?
- Use mirrors on both sides
- Back towards the driver's side, where you can see better
- Look at your path
- Use a helper (Correct answer)
Correct answer: Use a helper
When backing a large commercial vehicle, blind spots are extensive and dangerous. While using mirrors and backing towards the driver's side are helpful techniques, the absolute best method to avoid blind spots and ensure safety is to use a helper, or spotter. A helper can provide clear guidance and alert the driver to obstacles or hazards that are not visible in the mirrors, significantly reducing the risk of an accident.
Question 3: Which of the following is NOT an appropriate reason to flash your braking lights?
- To warn drivers behind you when you need to slow down
- To alert drivers behind you that there are hazards ahead
- To signal to tailgaters that they are too close to your vehicle (Correct answer)
- To warn vehicles approaching you from behind that you are driving slowly
Correct answer: To signal to tailgaters that they are too close to your vehicle
Flashing your brake lights is an important safety signal used to warn drivers behind you of slowing speeds or upcoming hazards. However, using them to signal annoyance or "punish" a tailgater is not appropriate and can be dangerous. This action can be misinterpreted as actual braking, potentially causing a rear-end collision, or it could escalate an already aggressive situation. Instead, it's safer to increase your own following distance and allow the tailgater to pass.
Question 4: You are driving a 50 foot truck at 38 MPH, how much space (in seconds) should you keep in front of you?
- 3 seconds
- 6 seconds
- 4 seconds
- 5 seconds (Correct answer)
Correct answer: 5 seconds
The standard rule for determining a safe following distance for commercial vehicles is to allow one second for every 10 feet of vehicle length. For a 50-foot truck, this calculation yields 5 seconds (50 feet / 10 feet per second). Since the truck is traveling at 38 MPH, which is not above 40 MPH, no additional second is required, making 5 seconds the correct safe following distance.
Question 5: Which of the following is NOT a recommended action to take when confronted by an aggressive driver?
- Ignore them and refuse to react to any of their gestures
- Make eye contact and motion to them that you are calling the authorities (Correct answer)
- Make every attempt to get out of their way
- Do not let your pride and ego affect your actions
Correct answer: Make eye contact and motion to them that you are calling the authorities
When confronted by an aggressive driver, the safest course of action is to avoid any direct engagement that could escalate the situation. Making eye contact or gesturing, such as motioning that you are calling authorities, can be perceived as confrontational and provoke further aggression from the other driver. Instead, it is recommended to ignore them, make every effort to safely get out of their way, and report their behavior to authorities only when it is safe to do so and without direct interaction.
Question 6: When driving in very hot temperatures, you should:
- Check your tires every 2 hours or every 100 miles
- Let your tires cool down (remain stopped) if they are too hot to touch
- Insure that you have enough antifreeze in the system
- All of the above (Correct answer)
Correct answer: All of the above
Driving in very hot temperatures places extra stress on a vehicle. Checking tires regularly helps prevent blowouts due to increased pressure and heat. Allowing overheated tires to cool down prevents damage and potential failure. Ensuring sufficient antifreeze is present is also crucial, as antifreeze raises the boiling point of the coolant, preventing the engine from overheating in extreme heat.
Question 7: Shifting into a lower gear and removing your foot off of the accelerator to slow your vehicle is known as?
- Double clutching
- Engine braking (Correct answer)
- Anti-lock braking
- Brake fade
Correct answer: Engine braking
Engine braking is the process of using the engine's resistance to slow down a vehicle. This is achieved by shifting into a lower gear and removing your foot from the accelerator, which causes the engine to work against the vehicle's momentum, helping to control speed without relying solely on the service brakes.
Question 8: Which of the following statements is FALSE?
- You can almost always turn to miss an obstacle more quickly than you can stop
- Stopping is not always the safest thing to do in an emergency
- If a tire blows, you should put the brakes on hard to stop quickly (Correct answer)
- Antilock Braking Systems (ABS) only activate when wheels are about to lock
Correct answer: If a tire blows, you should put the brakes on hard to stop quickly
If a tire blows, applying the brakes hard can cause the vehicle to swerve violently or lose control, especially with a sudden loss of stability. The correct procedure is to hold the steering wheel firmly, stay off the brake, and allow the vehicle to slow down gradually while maintaining control, then pull over safely.
Question 9: Which of the following are possible causes of tire fires?
- Loose fuel connections or under-inflated tires
- Dual tires that touch and under-inflated tires (Correct answer)
- Improperly loaded cargo and dual tires that touch
- Poor cargo ventilation or short circuits
Correct answer: Dual tires that touch and under-inflated tires
Dual tires that touch can rub against each other, generating excessive friction and heat, which can ignite the rubber. Under-inflated tires flex more than properly inflated ones, leading to increased internal heat buildup. Both of these conditions create enough heat to potentially cause a tire fire.
Question 10: The average person requires how many hours of sleep per 24 hour period?
- 7 or 8 (Correct answer)
- 8 or 9
- 6 or 7
- 5 or 6
Correct answer: 7 or 8
Most adults, including commercial drivers, require 7 to 8 hours of sleep per 24-hour period to maintain optimal alertness and cognitive function. Consistent sleep deprivation can lead to fatigue, impaired judgment, and an increased risk of accidents, making adequate rest essential for safe driving.
CDL General Knowledge Practice Test 3
Which of the following is NOT a part of the steering system?