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 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
Passing Score
15. The trailer hand valve should be used:
Explanation
The trailer hand valve should be used only to test the trailer brakes. It should not be used while driving because it may cause the trailer to skid.
16. Avoid needing to make sudden lane changes by:
Explanation
Making a sudden lane change can be dangerous when driving a combination vehicle. Avoid the need to make a sudden lane change by looking down the road for upcoming obstacles that will require you to change lanes.
17. If you need to back your trailer but cannot back up in a straight path, you should:
Explanation
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 colors are being used to distinguish glad hands, which color is used for service lines?
Explanation
When trailer air lines are color-coded, the service lines are generally blue and the emergency lines are generally red.
19. When coupling a trailer:
Explanation
When coupling, make sure you couple matching glad hands. They are often color-coded to help drivers avoid mistakes. Typically, blue is used for service lines and red is used for emergency lines.
20. A tractor protection valve is:
Explanation
