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 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 20

Passing Score 16

1. Shut-off valves:

Prevent air from escaping air brake systems.

Prevent air from entering air brake systems.

Override vehicles that are out of control.

Shut-off valves are used in air supply lines to control the passage of air from one trailer to another. The rear shut-off valve should always be closed to prevent air from leaving the braking system.

2. Fully-loaded rigs:

Are less likely to roll over than empty rigs.

Are more likely to roll over than empty rigs.

Are just as likely to roll over as empty rigs.

Fully-loaded rigs are more vulnerable to rolling over than empty rigs because the weight of the cargo gives the vehicles higher centers of gravity.

3. The trailer hand valve should not be used while you are driving because:

It will disconnect from the vehicle.

You will stop the vehicle too quickly.

It can cause a skid.

Never use the trailer hand valve while operating your vehicle. Using the trailer hand valve while driving can cause your trailer to skid.

4. Older trailers are not equipped with spring brakes. This means that if the air supply for a vehicle's air braking system leaks away:

The trailer will stop normally.

The trailer will not have brakes.

The trailer will speed up.

Older trailers do not have spring brakes. This means that if the air supply in an older trailer's air tank has leaked away, there will be no working brakes connected to the trailer and its wheels will turn freely.

5. If a load is placed on one side of a trailer, the trailer:

May lean during turns.

May add extra support during turns.

May be easier to steer during turns.

Positioning the weight of a load on one side of a trailer may cause the trailer to lean to that side, increasing the risk of a rollover during turns and lane changes.

6. If you are backing and become unsure about your path of travel, you should:

Continue backing.

Stop and get out to look.

Continue backing, but more slowly than before.

If you are unsure of your path while you are driving in reverse, you should stop, exit the vehicle, and recheck your path of travel.

7. Rollovers happen when:

You drive too slowly.

You are stopped.

You take a turn too fast.

Rollovers are caused by operators turning too fast. To avoid rolling over, drive slowly on entrance ramps, on exit ramps, and around corners. Avoid making quick lane changes when towing trailers.

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