Directions: 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.

May lean, and could result in a rollover.
May add extra support during turns.
Have improved braking.
Have improved steering.

Cause the trailer to disconnect.
Cause steering problems.
Cause braking problems.
Affect the lights.

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.

Using the air brakes.
Using wheel chocks.
Parking near a wall.
Parking on a slight incline.

One air line.
Two air lines.
Three air lines.
Four air lines.

District Of Columbia CDL Permit Test - Combination

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

Failure to keep the fifth wheel plate properly greased could:

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

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

A combination vehicle has:

Avoid needing to make sudden lane changes by:

In a combination rig, it is best to make:

Number of questions:	20
Passing score:	16

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.

Quick, sudden stops.
Sharp turns.
Quick accelerations.
Slow, planned stops.