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 Commercial Driver License.. Read More

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 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 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

1. To find out if a vehicle that was built before 1998 has an Anti-Lock Braking System (ABS), you can:

Pump the air brakes to activate the ABS.

Look into the back of the fifth wheel.

Check for wheel speed sensors coming from the back of the brakes.

If you are operating a vehicle built before 1998 and are unsure if the trailer has an Anti-Lock Braking System (ABS), you can check under the trailer for wheel speed sensors coming from the back of the brakes.

2. Pushing in the trailer air supply control will:

Supply the trailer with air.

Deactivate the air brakes.

Prevent the vehicle from skidding.

Push in the trailer air supply control to supply the trailer with air. Pull out the trailer air supply control to turn off the air supply and activate the emergency brakes.

3. Rollovers happen when:

Drivers turn too quickly.

Drivers turn too slowly.

It is raining.

Rollovers occur when drivers turn or change lanes too quickly.

4. If a trailer begins to skid, it is best for the driver to:

Release the brakes.

Accelerate.

Quickly turn the steering wheel in one direction, then in the other.

If your trailer begins to skid, you should release the brakes to regain traction. The trailer will begin to straighten out once the wheels begin to grip the road again.

5. Rearward amplification refers to:

The amount of noise projected to the rear of a vehicle.

The cause of the "crack-the-whip" effect.

The number of trailers that can be pulled by a tractor.

Vehicles with trailers are vulnerable to rollover due to the "crack-the-whip" effect, which is caused by rearward amplification.

6. When coupling a trailer, you should:

Couple together the proper glad hands.

Couple glad hands with any other glad hands.

Leave one pair of glad hand loose.

When coupling air brake hoses, you should make sure the proper pairs of gland hands are connected. They are sometimes color-coded to help drivers avoid mistakes. Typically, blue is used for service lines and red is used for emergency lines.