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. A combination vehicle has ____ air line(s).
Explanation
Every combination vehicle has two air lines: the service line and the emergency line.
16. What is a bobtail tractor?
Explanation
Tractors without semi-trailers are referred to as "bobtail tractors." Bobtail tractors are difficult to operate and drivers must exercise caution.
17. When driving while pulling trailers, you should:
Explanation
You should always steer gently and smoothly while pulling a trailer. Making sudden steering moves could cause the trailer to tip over.
18. When you are pulling a trailer, the air supply control lever should be in its ____ position.
Explanation
Tractor protection controls in older vehicles may be operated by levers instead of knobs. If an air supply control is set in its "normal" position, it is properly set for you to pull a trailer.
19. The trailer hand valve should not be used while you are driving because:
Explanation
Never use the trailer hand valve while operating your vehicle. Using the trailer hand valve while driving can cause your trailer to skid.
20. When coupling, after you've connected the air lines to the trailer, you should:
Explanation
