Instructions

Combination

All applicants who are applying for a Class A CDL should be prepared to take the Combination test. This test covers information found in Section 6 of the Maryland Commercial Driver License Manual. Section 6 provides the information needed to safely operate tractor-trailers, doubles, triples, and straight trucks with trailers. The test is made up of 20 multiple-choice and true/false questions, and applicants will need to correctly answer a minimum of 16 questions to pass. The Combination test is not a replacement for the Double/Triple endorsement test.

Number of Question 20

Passing Score 16

8. To help prevent rollovers, you should:

Accelerate quickly after stopping.

Drive slowly around turns.

Keep the load near the back of the trailer.

Keep the load on one side of the trailer.

To lower the risk of a rollover, load your cargo as closely to the ground as possible. To further reduce this risk, take curves and corners slowly.

9. Trailers with low underneath clearance may be difficult to drive:

On interstate highways.

Over railroad crossings.

On dirt roads.

At the posted speed limit.

Railroad-highway crossings may be difficult to cross when pulling a trailer with a low underneath clearance. In particular, both low-slung units and single-axle tractors pulling long trailers are especially challenging to drive over raised crossings.

10. A loss of air pressure in the emergency line will cause:

The service brakes to activate.

The tractor protection valve to close.

The rear trailer to detach from the combination.

The suspension springs to extend.

The tractor protection valve keeps air in the trailer's braking system should the trailer break away or develop a leak. A loss of air pressure in the emergency line will cause the tractor protection valve to open and the emergency trailer brakes to activate.

11. When backing a trailer, you must first turn the steering wheel:

In the direction you want the trailer to go.

In the direction opposite of where you want the trailer to go.

To the left.

When backing a vehicle without a trailer, a driver must turn the vehicle in the direction that they want to go. However, when backing with a trailer, the driver must begin by turning in the opposite direction. Once the trailer starts to turn, they should turn the wheel in the other direction to follow the trailer.

12. The emergency air line supplies air to the:

Relay valves.

Trailer air tanks.

Signal line.

The emergency air line (also known as the supply line) has two functions. The first is to supply air to the trailer air tanks, and the second is to control the emergency brakes on combination vehicles.

13. If a load is placed on one side of a trailer, the trailer:

May lean, and could result in a rollover.

May add extra support during turns.

Have improved braking.

Have improved steering.

If the weight of a load is placed primarily one side of a trailer, the trailer may lean, increasing the risk of a rollover.

14. What is the tractor protection valve?

A valve that keeps air in the brake system should a bad leak occur

A valve that prevents the trailer from being accidentally released

A valve that prevents the vehicle from going too fast

A tractor protection valve keeps air in a tractor or truck air brake system should the trailer break away or develop a bad leak. The valve will close automatically if the pressure drops to an unsafe level.

Grade This Section

See the exact questions that will be on the 2024 Maryland DMV exam.

99.2% of people who use the cheat sheet pass the FIRST TIME

Click Here
Full Cheat Sheet Unlock Your Exclusive Cheat Sheet!