FREE MD CDL Combination Test (2024)

1. Cargo should be properly covered:

to protect people from spilled cargo.
to block your view or someone else’s.
to protect the weather from the cargo.
All of the above.

2. To know how much space you should keep in front of you when driving at speeds below 40 mph, one good rule says you need at least ______ for each ______ of vehicle length.

1 second; 10 feet
1 second; 5 feet
2 seconds; 10 feet
3 seconds; 50 feet

3. In vehicles with air brakes, the tractor protection valve:

is used to connect the service and emergency air lines from the truck/tractor to the trailer.
keeps air in the tractor or truck brake system.
carries air, which is controlled by the trailer hand brake or the foot brake.
provides the air pressure used to operate trailer brakes.

4. The wheels of a large combination vehicle are more likely to lock up when:

the vehicle is heavily loaded.
the vehicle is lightly loaded.
you are traveling in very hot weather.
the trailer has new tires.

5. What is the proper following distance for a 50 foot truck traveling at 50 mph?

6 seconds
5 seconds
10 seconds
25 seconds

6. If a vehicle is equipped with ABS, when you start the engine:

the trailer emergency brakes will come on.
the wheels will lock up.
the spring brakes will come on.
the ABS indicator light on the dash should come on and then turn off.

7. A bridge formula permits less maximum axle weight for axles that:

are further apart than normal
have a high center of gravity
are closer together
have poor weight balance

8. In your mirror, you see a car approaching from the rear. The next time you check your mirror, you don't see the car. If you wish to change lanes, you should:

wait until you are sure the car isn't in your blind spot.
assume the car left the roadway and change lanes as normal.
ease into the other lane slowly so the other car can get out of the way.
None of the above.

9. If your trailer starts to skid, you should:

release the brakes.
pump the brakes.
lock the brakes.
steer in the opposite direction.

10. Before driving a vehicle with a dual air brake system, you should allow time for the air compressor to build up a minimum of ____ pressure in both the primary and secondary systems.

50 psi
35 psi
150 psi
100 psi

Number of questions:	20
Correct answers to pass:	16
Passing score:	80%

MD CDL COMBINATION PRACTICE TEST

MD CDL Combination Test