FREE District of Columbia CDL Doubles Triples Practice Test (2024)

1. An item that is 15 feet long placed on a flatbed trailer should have at least:

2. When driving at night, you should use ________ when you can.

3. If you go twice as fast, your stopping distance will increase by:

4. When approaching a double railroad track, you should:

rely upon the presence of warning signals.
remember that a train on one track may hide a train on the other track.
remember that trains may be more frequent.
expect to hear a train when it's approaching.

5. The earliest way to recognize that your trailer has started to skid is:

by releasing the brakes.
by checking your mirrors.
by hearing squeaking noises from the wheels.
by checking the jackknife sensor.

6. With low beams, drivers can see ahead about:

7. If you cannot make a right turn without entering another traffic lane, you should:

turn wide as you complete the turn.
turn wide before you start the turn.
watch out for vehicles coming toward you and back up for them.
swing wide to the left before starting the turn.

8. On front tires, tread should be at least:

9. Your mirrors should be adjusted so that:

the rear of the vehicle is visible in the mirror.
no part of the vehicle is visible in the mirror.
a part of the vehicle is visible in the mirror.
more than half of the mirror shows the vehicle.

10. An alcohol evaporator:

to hold compressed air.
protects the air brake system from too much pressure.
is used to reduce the risk of ice in air brake valves and other parts during cold weather.
used to reduce the chance of the front wheels skidding.

DISTRICT OF COLUMBIA CDL DOUBLES TRIPLES PRACTICE TEST