Tractor protection controls in older vehicles may be operated by levers instead of knobs. If an air supply control is set in its "emergency" position, the air supply will be stopped and the trailer emergency brakes will be applied.

Apply the trailer emergency brakes.

Because the weight of cargo gives them a higher center of gravity, fully-loaded rigs are 10 times more likely to roll over in a crash than empty rigs.

Are more likely to roll over than empty rigs.

Are less likely to roll over than empty rigs.

Are more likely to roll over than empty rigs.

Are just as likely to roll over as empty rigs.

When driving a tractor-trailer combination equipped with an Anti-Lock Braking System (ABS), you should brake in the same manner that you would if operating a vehicle without ABS.

Brake as you would when driving a vehicle without ABS.

Not depress the brakes as much as you would when driving a vehicle without ABS.

Use extra braking force to ensure the ABS kicks in.

Brake as you would when driving a vehicle without ABS.

Try to not brakes as often as you would when driving a vehicle without ABS.

When coupling, make sure you couple matching glad hands. They are often color-coded to help drivers avoid mistakes. Typically, blue is used for service lines and red is used for emergency lines.

Make sure to couple matching glad hands.

Any glad hand can be connected to any other glad hand.

It is best to leave one glad hand unattached.

Only one set of glad hands should be connected.

Trailers and converter dollies built on or after March 1, 1998 are required to have Anti-Lock Braking Systems (ABS). This will be indicated by the presence of a yellow malfunction lamp. You can determine if older trailers have ABS by checking under the trailers for ECU and wheel speed sensor wires coming from the back of the brakes.

Check under the trailer for wheel speed sensors coming from the back of the brakes.

Try driving on a slippery surface and see if ABS kicks in.

Remove a tire and look for the ABS sensor on the axle.

Combination Vehicles Practice Test | North Dakota 2025 #2

Train for FREE online with our North Dakota CDL combination vehicle test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a ND combination license in 2025, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that DMV requirements for issuing a combination license may vary from state to state.

Number of Question 20

Passing Score 16

Number of Tests 20

Combination Vehicles Practice Test | North Dakota 2025 #2

1 . An air supply control in its "emergency" position will:

2 . A combination vehicle has:

3 . Fully-loaded rigs:

4 . When driving a trailer with ABS, you should:

5 . Using the trailer hand brake while experiencing a trailer jackknife will:

6 . When coupling a trailer:

7 . If unsure if a trailer is equipped with ABS, you can:

Search the best driving school in your neighbourhood