Alabama CDL Class A Practice Test – 20 Questions with Answers

B. To identify safety defects before driving

A pre-trip inspection helps identify equipment problems that could make the vehicle unsafe to operate.

B. To protect the tractor's air supply if the trailer separates

The tractor protection system helps prevent loss of air from the tractor if the trailer breaks away or develops a serious air-line problem.

B. When the rear wheels of the trailer follow a shorter path than the tractor in a turn

During a turn, the trailer wheels generally track inside the path of the tractor, which is known as off-tracking.

B. Get out and check the area when necessary

Because backing is one of the most hazardous maneuvers for commercial drivers, you should inspect the area and use a spotter when appropriate.

A. To connect the tractor to the trailer

The fifth wheel provides the coupling connection between the tractor and the semi-trailer.

A. The fifth-wheel locking mechanism

The fifth-wheel jaws or locking mechanism must properly secure the trailer's kingpin to prevent separation.

B. It prevents cargo from shifting or falling from the vehicle

Properly secured cargo helps maintain vehicle stability and prevents cargo from moving, falling, or becoming a hazard.

A. The vehicle's center of gravity becomes higher

A higher center of gravity increases the risk of rollover, especially during turns or sudden maneuvers.

A. The time needed for air pressure to reach the brake components after the brake pedal is applied

Air brakes have a slight delay because compressed air must travel through the system before the brakes fully apply.

B. The driver should safely stop and address the problem

A low-air warning indicates that air pressure has reached a potentially dangerous level and should not be ignored.

B. To help control speed and reduce reliance on service brakes

Selecting an appropriate lower gear provides engine braking and helps prevent excessive use and overheating of the service brakes.

B. Slow down before entering the turn

Large vehicles have a higher rollover risk, so speed should be reduced before entering a sharp turn.

C. Ease off the accelerator and avoid sudden movements

Sudden braking, steering, or acceleration can cause a loss of control. Gradually reducing acceleration helps the tires regain traction.

A. Commercial vehicles have large blind spots

Large commercial vehicles have areas around them that may not be visible to the driver, making careful mirror checks essential.

C. Continue to the next exit and safely reroute

Missing an exit is not a reason to make a dangerous maneuver. Continue safely and find another route.

A. Large vehicles require more stopping distance

Heavy commercial vehicles generally require more distance to stop, particularly at higher speeds or in poor road conditions.

B. Stop before the crossing until you can completely clear the tracks

Never enter a railroad crossing unless there is enough room for the entire vehicle combination to clear the tracks.

B. Move to the right and stop when safe

Drivers should yield to emergency vehicles using audible and visual signals and move to the right and stop when safe.

A. To identify changes or defects that could affect safe operation

Periodic inspections can reveal loose, damaged, leaking, or otherwise unsafe components that may have developed during the trip.

B. Prioritize safe vehicle control and comply with traffic and safety requirements

Safe CDL operation requires maintaining control, understanding the vehicle's limitations, following traffic laws, and conducting required inspections.