FREE MD CDL Doubles/Triples Test 2024 (Practice Test)

1. Combination vehicles usually:

require more driving skill than single CMVs.
are shorter than single than single CMVs.
are easier to drive than single than single CMVs.
All of the above.

2. When transporting cargo, cargo securement must be checked within the first _____ miles of a trip and every _____ miles after.

3. A trailer jackknife is more likely to happen when the trailer is:

4. The tractor protection valve:

controls the emergency brakes on combination vehicles.
supplies air to the trailer air tanks.
works the trailer brakes.
keeps air in the tractor brake system should the trailer break away or develop a bad leak.

5. Weight that is loaded so there is a high center of gravity:

causes greater chance of rollover.
makes a vehicle easier to handle.
reduces the chance that the load will shift to the side or fall off.
All of the above.

6. By pushing the trailer air supply control knob in, you:

supply the tires with air.
supply the trailer with air.
shut the air off and put on the trailer emergency brakes.
keeps air in the tractor or truck brake system.

7. If the engine catches fire, you should:

turn off the engine as soon as you can.
avoid shooting foam from the vehicle's underside.
open the hood as soon as you can.
pull into a service station and notify the emergency services.

8. In a combination vehicle, ________ is most likely to turn over.

the last trailer
the trailer behind the tractor
the tractor
All of the above.

9. To make the brakes work, air brakes use:

10. You are driving a double. Before entering traffic, you should:

turn on your headlights.
assume there is enough room to merge into traffic.
always come to a complete stop.
make sure you have a large enough gap before entering or crossing traffic.

DOUBLES TRIPLES TEST MD - CDL PRACTICE TEST