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 have one hour to correctly answer a minimum of 16 questions. The Combination test is not a replacement for the Double/Triple endorsement test.

Number of Question 20

Passing Score 16

15. Failure to keep the fifth wheel plate properly greased could:

Cause the trailer to disconnect.

Cause steering problems.

Cause braking problems.

Affect the lights.

Failure to keep the fifth wheel plate properly lubricated can create friction between the tractor and trailer, causing steering problems.

16. If a trailer begins to skid, the driver should:

Lock the brakes.

Release the brakes.

Steer in the opposite direction.

Accelerate.

If your trailer starts to skid while you are braking, you should release the brakes and allow them to begin to regain traction. Once its wheels have regained their grip on the road, the trailer will begin to straighten out and follow the tractor.

17. If you need to back your trailer but cannot back up in a straight path, you should:

Back toward the passenger's side.

Back toward the driver's side.

Swerve back and forth while backing.

Always turn to your right.

If you need to back your trailer but cannot back up in a straight path, you should back on a curved path toward the driver's side of the vehicle. This will permit you the best possible visibility while backing.

18. If your trailer goes off course while you are backing, you should:

Continue the backing process without changing anything.

Pull the truck forward, readjust, and start backing again.

Get out of the truck and move the trailer into the right position.

Turn the steering wheel all the way to the left until the trailer straightens out.

If your trailer goes off course while you are backing, you should pull your truck forward and reposition your vehicle as needed before continuing to back up.

19. Simply changing lanes can cause:

A “crack-the-whip” effect, resulting in a rollover.

A trailer to straighten out.

Confusion over which lane the driver is hoping to use.

Other drivers to reduce their speed.

Due to the "crack-the-whip" effect caused by rearward amplification, changing lanes too quickly in a combination vehicle can result in a rollover.

20. In a double or triple combination:

Cargo weight must be evenly distributed between all trailers.

The heaviest trailer should be positioned directly behind the cab.

The heaviest trailer should be positioned in the rear.

The weight of the trailers does not matter.

When positioning trailers in a combination, the most heavily-loaded trailer should be the closest to the tractor. The lightest trailer should be positioned in the rear.

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