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 one hour 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. Failure to keep the fifth wheel plate properly greased could:

Cause the trailer to disconnect.

Cause steering problems.

Cause braking problems.

Affect the lights.

Failure to keep the fifth wheel plate properly lubricated can create friction between the tractor and trailer, causing steering problems.

2. If a parked trailer does not have spring brakes, you should keep the trailer from moving by:

Using the air brakes.

Using wheel chocks.

Parking near a wall.

Parking on a slight incline.

If a parked trailer does not have spring brakes, wheel chocks should be used to prevent it from moving. Air brakes can only hold a parked trailer for as long as there is air pressure remaining in the air tanks, so wheel chocks will ensure safety.

3. A combination vehicle has:

One air line.

Two air lines.

Three air lines.

Four air lines.

Combination vehicles have two air lines: a service line and an emergency line.

4. Avoid needing to make sudden lane changes by:

Using your horn to encourage other drivers to move out of your lane.

Only driving slower than the posted speed limit.

Watching the road ahead while driving.

Pulling off the road and waiting when there is high traffic.

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.

5. During a trip, which shut-off valves should be open?

All shut-off valves should be open.

The rear shut-off valves should be open.

All shut-off valves should be in the open position, except the rear shut-off valves.

No shut-off valves should be open.

When starting a trip, be sure that all shut-off valves are in the open position, except for the last valves on the rear trailer. It is important that air reaches the brakes on all trailers and that the air is not able to escape from the back of the vehicle.

6. In a combination rig, it is best to make:

Quick, sudden stops.

Sharp turns.

Quick accelerations.

Slow, planned stops.

When driving a combination vehicle, it is important to brake well in advance and look far ahead of your vehicle to avoid the need for sudden stops. Making habits of these actions will help you prevent your trailer from jackknifing.