CDL General Knowledge Practice Test1 — Questions and Answers
Question 1: What is the most important reason for doing a vehicle inspection?
- To save you money by preventing costly repairs
- Safety for yourself and other road users (Correct answer)
- Federal and state laws require you to inspect your vehicle
- To insure that you will achieve the best gas mileage
Correct answer: Safety for yourself and other road users
The most important reason for conducting a vehicle inspection is to ensure safety for yourself and other road users. Regular inspections identify potential mechanical issues before they lead to breakdowns or accidents, protecting the driver, passengers, and others on the road. While other reasons like legal compliance and preventing costly repairs are valid, safety is the paramount concern in commercial driving.
Question 2: When backing your vehicle, which of the following is NOT recommended
- Back as slow as possible
- Back towards the right side (Correct answer)
- Use the lowest reverse gear
- Back and turn towards the driver's side
Correct answer: Back towards the right side
When backing a vehicle, it is generally NOT recommended to back towards the right side. Backing towards the driver's side (left) offers better visibility through the driver's side mirror and direct line of sight, making it easier to judge distances and obstacles. Backing to the right often involves greater blind spots and reduced visibility, significantly increasing the risk of an accident.
Question 3: It is important for driving safety to always be looking ahead. Which of the following is NOT a recommended time/distance that you should be looking ahead?
- About 12-15 seconds
- About one block for city driving
- About 1/4 mile for open highway driving
- About 5 car lengths on the highway (Correct answer)
Correct answer: About 5 car lengths on the highway
CDL safety guidelines emphasize looking 12-15 seconds ahead to allow ample time for hazard perception and reaction. While options A, B, and C represent appropriate look-ahead distances for various driving conditions, "about 5 car lengths on the highway" is far too short. This distance provides insufficient time to react to potential dangers, making it an unsafe and therefore not recommended practice for commercial drivers.
Question 4: You are driving a 40 foot truck at 35 MPH, how much space (in seconds) should you keep in front of you?
- 3 seconds
- 4 seconds (Correct answer)
- 5 seconds
- 6 seconds
Correct answer: 4 seconds
The standard rule for commercial vehicles is to maintain a following distance of at least one second for every 10 feet of vehicle length. For a 40-foot truck, this calculation yields 4 seconds (40 feet / 10 feet per second). Since the speed is 35 MPH (not exceeding 40 MPH), no additional second is required, making 4 seconds the correct safe following distance.
Question 5: The act of operating a motor vehicle in a selfish, bold, or pushy manner, without regard for the rights or safety of others is known as?
- Defensive driving
- Road rage
- Aggressive driving (Correct answer)
- Distracted driving
Correct answer: Aggressive driving
The description provided perfectly defines aggressive driving, which involves operating a vehicle in a selfish, bold, or pushy manner without considering others' safety or rights. This behavior includes actions like tailgating, improper lane changes, and speeding. It is distinct from road rage, which is a more extreme and violent reaction to driving situations.
Question 6: You should check your tires every ____ or every ____ when driving in very hot weather.
- 1 hour, 50 miles
- 2 hours, 100 miles (Correct answer)
- 3 hours, 200 miles
- 5 hours, 250 miles
Correct answer: 2 hours, 100 miles
Commercial drivers must regularly inspect their tires to ensure safety, especially in hot weather where tire temperatures and pressure can increase significantly. The recommended guideline for these checks is every 2 hours or every 100 miles. This frequent inspection helps identify potential issues like under-inflation or overheating before they lead to dangerous tire failures.
Question 7: Which of the following factors is NOT used to determine your safe speed when going down a long steep downgrade?
- Length and steepness of grade
- Weather
- Total weight of the vehicle and cargo
- Time of day (Correct answer)
Correct answer: Time of day
When descending a long, steep downgrade, a commercial driver's safe speed is determined by several critical factors that affect vehicle control and braking. These include the grade's length and steepness, current weather conditions, and the total weight of the vehicle and its cargo. The time of day, however, does not physically influence the vehicle's performance or the forces acting upon it during a downgrade, making it an irrelevant factor for determining safe speed.
Question 8: With the controlled braking method, you _____?
- Lightly apply braking pressure
- Apply the brakes as hard as you can without locking the wheels (Correct answer)
- Apply the brakes all the way until the wheels lock up, release the brakes and apply them again when the wheels start to roll again
- Repeatedly tap the brakes as fast as you can
Correct answer: Apply the brakes as hard as you can without locking the wheels
The controlled braking method is a technique used to stop a vehicle quickly while maintaining steering control, especially in emergencies. It involves applying the brakes as firmly as possible without causing the wheels to lock up. This allows the driver to slow down effectively while still being able to steer around obstacles, unlike stab braking which involves locking and releasing the brakes.
Question 9: Which of the following is NOT a basic step to be taken at a crash scene?
- Notify authorities
- Care for the injured
- Gather the contact information of all the drivers involved (Correct answer)
- Protect the area
Correct answer: Gather the contact information of all the drivers involved
At a crash scene, the immediate and basic steps prioritize safety and emergency response. These include protecting the area to prevent further incidents, caring for any injured individuals, and promptly notifying authorities. While gathering contact information is a necessary step for insurance and legal purposes, it is typically done after the immediate safety and emergency response actions have been addressed, making it not one of the *basic* initial steps.
Question 10: Which contains more alcohol: a 12-ounce glass of 5% beer, a 5-ounce glass of 12% wine or a 1 1/2-ounce shot of 80 proof liquor.
- 12-ounce glass of 5% beer
- 5-ounce glass of 12% wine
- 1 1/2-ounce shot of 80 proof liquor
- They all contain the same amount of alcohol (Correct answer)
Correct answer: They all contain the same amount of alcohol
These three drink types represent standard serving sizes, each containing roughly the same amount of pure alcohol, approximately 0.6 ounces. A 12-ounce glass of 5% beer, a 5-ounce glass of 12% wine, and a 1 1/2-ounce shot of 80 proof (40% alcohol) liquor are all considered one standard drink. This equivalence is crucial for understanding alcohol consumption and its effects on the body.
Question 11: Vehicle handling can become unsafe if the weight is not properly balanced. Hard steering can be caused by
- Too little weight on the driving axles
- Too much weight on the steering axles (Correct answer)
- Under loaded front axles
- High center of gravity
Correct answer: Too much weight on the steering axles
Vehicle handling is significantly affected by proper weight distribution. When there is too much weight on the steering axles, typically the front axles, it can make the steering feel heavy and difficult to control. This excessive load can strain steering components, reduce tire responsiveness, and make it harder for the driver to maneuver the vehicle safely.
CDL General Knowledge Practice Test1
What is the most important reason for doing a vehicle inspection?