CDL Doubles and Triples 5

Question 1

Why is lane changing riskier with triples than with a single trailer?

Accepted Answer

Rearward amplification makes the rear trailers swing more

Answer

Each trailer adds amplification, making sudden lane changes dangerous.

Question 2

When driving downhill with doubles, you should:

Accepted Answer

Select a lower gear before starting down and use proper braking

Answer

Using a lower gear and controlled braking keeps speed safe and avoids brake fade.

Question 3

Which action best reduces trailer sway and rollover risk on curves with doubles?

Accepted Answer

Slow down before entering the curve

Answer

Reduced speed lowers lateral forces on the rear trailer.

Question 4

Which of these should NOT be used to hold a parked combination?

Accepted Answer

The trailer hand valve

Answer

Air can leak off the hand valve, releasing the brakes, so never rely on it for parking.

Question 5

In a skid, why is a rig with a lighter trailer in front more dangerous?

Accepted Answer

It is less stable and the rear heavier trailer can push the front trailer

Answer

A heavier rear trailer can swing or push the lighter front units.

CDL Practice Test