CDL Full Practice Test Part 20

1. A driver is operating an empty tractor-semitrailer with air brakes on a dry road. The driver applies the brakes moderately to stop for a traffic signal, but the vehicle takes noticeably longer to stop than expected. The driver then applies harder brake pressure, and the rear wheels lock briefly before ABS activates. What explains the longer stopping distance, and what should the driver have done differently?

2. A driver encounters heavy fog while operating a CMV on a highway. Visibility is reduced to approximately 200 feet. What is the correct procedure for headlight use in this situation?

3. During the cab check portion of a pre-trip inspection, a driver notices that the right-side convex mirror is cracked but still provides a partial view of the trailer’s right side. The driver decides to proceed with the trip, planning to replace the mirror at the next scheduled maintenance stop in three days. What should the driver do instead?

4. A driver is operating a CMV equipped with air brakes on a long highway route. The driver notices the air pressure gauge reading has dropped to 75 PSI during normal driving and continues to decline slowly despite no brake applications. The low-pressure warning light has not yet activated. What analysis best explains this situation and the required action?

5. A driver is traveling at 55 mph on a two-lane highway when a passenger vehicle suddenly cuts in front, leaving only 3 seconds of following distance. The road is dry and the CMV is moderately loaded. What is the safest response?

6. What is the “GOAL” principle in backing operations and why is it emphasized in CDL training?

7. A driver is making a right turn with a 53-foot trailer at a tight intersection. The tractor has begun the turn but the driver notices pedestrians standing near the curb in the path where the trailer’s rear wheels will track. What should the driver do?

8. During the engine compartment pre-trip inspection, the driver examines the radiator hoses. What hose condition indicates a defect that should be reported on the DVIR and requires repair before continued operation?

9. What is the primary function of the air compressor in a commercial motor vehicle’s air brake system?

10. A driver traveling at 55 mph in a 60-foot combination vehicle experiences a rear-wheel skid on a wet curve. The driver steers in the opposite direction of the skid and applies firm braking. The vehicle jackknifes and crosses into oncoming traffic. Which two errors caused this outcome?