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 have two hours 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
1. 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.
2. To find out if a vehicle that was built before 1998 has an Anti-Lock Braking System (ABS), you can:
Explanation
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.
3. Trailers built before ____ are not required to have spring brakes.
Explanation
Trailers built before 1975 are not required to have spring brakes. When parking a trailer without spring brakes, be sure to use wheel chocks to prevent the trailer from rolling.
4. In a vehicle equipped with an automatic tractor protection valve, the valve will pop out when air pressure drops to a level between:
Explanation
In vehicles equipped with an automatic tractor protection valve, the valve will pop out if air pressure drops to a level between 20 and 45 psi. When the valve pops out, the protection valve will close, stopping the flow of air.
5. More than half of all accident-related truck driver deaths are caused by:
Explanation
More than half of all accident-related truck driver deaths are a result of truck rollovers. To help prevent a rollover, be sure to load cargo low to the ground and centered on your rig. Take corners slowly and carefully.
6. Watching the road ahead:
Explanation
Making a sudden lane change can be dangerous while driving a combination vehicle. You can avoid the need to make a sudden lange change by looking down the road for upcoming obstacles that will require you to change lanes.
7. When braking while pulling a trailer equipped with anti-lock brakes, you should:
Explanation