SD CDL - South Dakota Commercial Drivers License Basic Vehicle Control Questions and Answers

Question 1

When backing a large commercial vehicle, what is the most important safety practice to follow?

Accepted Answer

Getting out of the vehicle to look at your path of travel before backing.

Answer

The most critical safety step before backing is to get out and walk around the vehicle (G.O.A.L. - Get Out And Look). This allows the driver to identify any obstacles, hazards, or changes in the environment that are not visible in the mirrors. Conditions can change quickly, and relying only on mirrors creates dangerous blind spots.

Question 2

You are driving a truck with a manual transmission. To accelerate smoothly from a stop, you should:

Accepted Answer

Slowly release the clutch while gently pressing the accelerator.

Answer

To achieve a smooth start in a manual transmission vehicle, the driver must coordinate the gradual release of the clutch with a gentle application of the accelerator. This allows the engine to engage with the transmission without jerking or stalling the vehicle. Releasing the clutch too fast or applying too much throttle will result in a rough, jerky start.

Question 3

Which of the following best describes the primary purpose of a vehicle's retarder?

Accepted Answer

To help slow the vehicle and reduce wear on the service brakes.

Answer

Retarders (such as engine brakes or exhaust brakes) are designed to help slow a vehicle, particularly on long downgrades, which reduces the need to use the service brakes. This helps prevent the service brakes from overheating and fading, and it reduces wear, ensuring the brakes are in good condition for when they are truly needed for stopping.

Question 4

A driver is preparing to make a right turn in a large truck. To execute the turn properly without hitting the curb, the driver must:

Accepted Answer

Swing wide to the left before starting the turn to allow the rear wheels to clear the corner.

Answer

Large vehicles exhibit "off-tracking," where the rear wheels follow a shorter path than the front wheels during a turn. To compensate for this and prevent the rear wheels from running over the curb or sidewalk, the driver must steer the front of the vehicle wide into the intersection, a maneuver often called a "button hook" turn.

Question 5

Under which condition should a driver AVOID using an engine retarder or "jake brake"?

Accepted Answer

When the roadway is wet, icy, or covered in snow.

Answer

Retarders apply braking force only to the drive wheels. On surfaces with poor traction, such as those that are wet, icy, or snow-covered, using the retarder can cause the drive wheels to lock up and skid, potentially leading to a loss of vehicle control. Therefore, retarders should be turned off in such conditions.

SD CDL - South Dakota Commercial Drivers License Practice Test

SD CDL - South Dakota Commercial Drivers License Practice Test

SD CDL - South Dakota Commercial Drivers License Basic Vehicle Control Questions and Answers