CLP General Knowledge Core Concepts 2 — Questions and Answers
Question 1: What is the minimum tread depth required for front tires on a commercial motor vehicle?
- 2/32 inch
- 4/32 inch (Correct answer)
- 6/32 inch
- 8/32 inch
Correct answer: 4/32 inch
Front tires on a CMV must have a minimum tread depth of 4/32 inch; all other tires require 2/32 inch.
Question 2: When should you use your vehicle's low beam headlights instead of high beams?
- When driving faster than 55 mph
- Within 500 feet of an oncoming vehicle or 300 feet behind another vehicle (Correct answer)
- Only in heavy rain or fog
- Whenever driving on a two-lane road
Correct answer: Within 500 feet of an oncoming vehicle or 300 feet behind another vehicle
You must dim to low beams within 500 feet of an approaching vehicle and within 300 feet when following another vehicle.
Question 3: A placarded hazardous materials vehicle must park how far from an open flame?
- 100 feet
- 200 feet
- 300 feet (Correct answer)
- 500 feet
Correct answer: 300 feet
Vehicles carrying hazardous materials must keep at least 300 feet from an open fire unless the road requires them to pass.
Question 4: Which of the following is NOT a sign of tire failure while driving?
- Thumping or vibration
- Steering that pulls to one side
- A sudden increase in fuel economy (Correct answer)
- The vehicle feels sluggish
Correct answer: A sudden increase in fuel economy
Improved fuel economy is not associated with tire failure; thumping, pulling, and sluggishness are all warning signs.
Question 5: What does a 'gross vehicle weight rating' (GVWR) represent?
- The maximum weight a vehicle can legally tow
- The maximum loaded weight the manufacturer specifies for a single vehicle (Correct answer)
- The combined weight of cargo only
- The weight of the vehicle when completely empty
Correct answer: The maximum loaded weight the manufacturer specifies for a single vehicle
GVWR is the maximum loaded weight a vehicle is designed to handle, as set by the manufacturer.
Question 6: What is the purpose of the 'glad hands' on a commercial vehicle?
- To secure the fifth wheel coupling
- To connect the air supply and service brake lines between a tractor and trailer (Correct answer)
- To lock the trailer's landing gear
- To attach safety chains during coupling
Correct answer: To connect the air supply and service brake lines between a tractor and trailer
Glad hands are the coupling devices used to connect the tractor's air lines to the trailer's air lines.
Question 7: Under federal hours-of-service rules, a property-carrying driver using the 60-hour/7-day limit must take how many consecutive hours off before restarting the 60-hour count?
- 8 hours
- 10 hours
- 24 hours
- 34 hours (Correct answer)
Correct answer: 34 hours
A 34-hour restart (consecutive off-duty hours) resets the 60-hour/7-day or 70-hour/8-day on-duty limit.
CLP General Knowledge Core Concepts 2
What is the minimum tread depth required for front tires on a commercial motor vehicle?