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
Passing Score

15. When driving a tractor-trailer equipped with ABS, you should:

Explanation
When driving a tractor-trailer combination equipped with an Anti-Lock Braking System (ABS), you should brake in the same manner that you would in a vehicle without ABS.

16. If colors are being used to distinguish glad hands, which color is used for emergency lines?

Explanation
When trailer air lines are color-coded, the service lines are generally blue and the emergency lines are generally red.

17. A tractor protection valve is:

Explanation
On combination vehicles with air brakes, the tractor protection valve keeps air in the tractor or truck brake system, should the trailer develop a bad leak or break away from the tractor.

18. While inspecting a coupling, you should go under the trailer and:

Explanation
While inspecting a coupling, you should go under the trailer and look into the back of the fifth wheel. Ensure that the fifth wheel jaws are secured around the shank of the kingpin.

19. Simply changing lanes can cause:

Explanation
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. When driving a combination rig, following distance should be:

Explanation
In comparison to driving a single vehicle, you should maintain an extended following distance when driving a combination rig. Combinations require longer stopping distances than smaller vehicles.
DMV Writen Test