SD CDL Combination Vehicle Operations 5

Question 1

When making a right turn in a tractor-trailer, you should:

Accepted Answer

Drive straight ahead until clear, then swing wide as you complete the turn

Answer

Go straight ahead until the rear clears the corner and swing wide at completion so cars can't slip in on your right.

Question 2

What is 'offtracking'?

Accepted Answer

Rear wheels following a different path than front wheels in a turn

Answer

Offtracking is when the rear wheels of a long vehicle follow a shorter path than the front wheels during turns.

Question 3

In a set of doubles, where should the heavier trailer be placed?

Accepted Answer

First, directly behind the tractor

Answer

The heaviest trailer should be in the first position, right behind the tractor.

Question 4

When pulling doubles, how should the shut-off valves (cut-out cocks) be set?

Accepted Answer

Open on front trailers, closed at the rear of the last trailer

Answer

Rear valves on front trailers must be open so air passes through, while those on the last trailer are closed.

Question 5

How can you verify air has reached the last trailer of a set of doubles?

Accepted Answer

Open the emergency line shut-off at the rear of the last trailer and listen for air

Answer

Briefly opening the emergency line valve at the rear of the last trailer and hearing air confirms the lines are open.

SD CDL - South Dakota Commercial Drivers License Practice Test