Commercial Driving General Knowledge 2 — Questions and Answers
Question 1: What is the 14-hour rule in Hours of Service regulations?
- You must sleep 14 hours between shifts
- You cannot drive beyond the 14th consecutive hour after coming on duty, following 10 hours off (Correct answer)
- You must take a 14-hour break every week
- You can drive 14 hours if you take breaks
Correct answer: You cannot drive beyond the 14th consecutive hour after coming on duty, following 10 hours off
The 14-hour rule limits the window in which driving can occur. Once you start your duty day, you have 14 hours before driving is no longer permitted, regardless of breaks taken.
Question 2: What is the required minimum tread depth for front tires on a commercial vehicle?
- 2/32 of an inch
- 4/32 of an inch (Correct answer)
- 6/32 of an inch
- 8/32 of an inch
Correct answer: 4/32 of an inch
Federal regulations require front tires on commercial vehicles to have at least 4/32-inch tread depth. Other tires require at least 2/32 inch.
Question 3: What is the purpose of a Driver Vehicle Inspection Report (DVIR)?
- To record fuel purchases
- To document vehicle condition at the end of each driving day and report any defects (Correct answer)
- To track delivery times
- To log weather conditions
Correct answer: To document vehicle condition at the end of each driving day and report any defects
The DVIR is a written report documenting the condition of the vehicle and any defects found. It must be completed at the end of each driving day.
Question 4: What blood alcohol concentration (BAC) is the legal limit for commercial drivers?
- 0.08%
- 0.04% (Correct answer)
- 0.02%
- 0.00%
Correct answer: 0.04%
Commercial drivers are held to a stricter BAC standard of 0.04%, which is half the legal limit for non-commercial drivers (0.08%).
Question 5: What is the 60/70-hour rule?
- You must work 60-70 hours per week
- You cannot drive after accumulating 60 hours in 7 days or 70 hours in 8 days on duty (Correct answer)
- You must rest 60-70 hours per week
- You can drive 60-70 mph on highways
Correct answer: You cannot drive after accumulating 60 hours in 7 days or 70 hours in 8 days on duty
The 60/70-hour rule limits total on-duty time. Drivers for carriers not operating every day are limited to 60 hours in 7 days; those operating every day are limited to 70 hours in 8 days.
Question 6: What must a commercial driver do when approaching a railroad crossing?
- Speed up to cross quickly
- Slow down and look both ways but never stop
- Stop within 50 feet but not less than 15 feet from the nearest rail if required by regulations (Correct answer)
- Honk the horn and proceed
Correct answer: Stop within 50 feet but not less than 15 feet from the nearest rail if required by regulations
Certain commercial vehicles must stop at railroad crossings between 15 and 50 feet from the nearest rail, look and listen for approaching trains, and proceed only when safe.
Commercial Driving General Knowledge 2
What is the 14-hour rule in Hours of Service regulations?