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 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 20

Passing Score 16

1. What is a bobtail tractor?

A tractor without a semi-trailer

A tractor with two semi-trailers

A tractor that travels faster than the speed limit

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:

Pump the air brakes to activate the ABS.

Look into the back of the fifth wheel.

Check for wheel speed sensors coming from the back of the brakes.

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.

1985

1975

1999

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:

20 and 45 psi.

75 and 105 psi.

50 and 65 psi.

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:

Rollovers.

Slippery roads.

Other drivers.

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:

Is more dangerous than only watching your mirrors.

Does not help you drive more safely.

Can help you avoid the need for sudden lane changes.

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:

Pump the brakes.

Use extra braking force to ensure the brakes kick in.

Brake as you would without anti-lock brakes.

When driving a tractor-trailer combination that is equipped with an Anti-Lock Braking System (ABS), you should brake in the same manner that you would if the vehicle was not equipped with ABS.

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