Trailers can overturn as a result of the "crack-the-whip" effect. The last trailer in a combination is the most prone to tip over due to this effect. Drivers should be aware of the rearward amplification of their specific vehicles and drive accordingly.

Be more effective than braking.

The easiest way to become aware that your trailer has begun to jackknife is to observe it in your mirrors. Checking your trailer in your mirrors will also allow you to spot any skidding at the earliest possible moment.

Checking the trailer in your mirrors.

Before a trip, ensure that air in the air brake system reaches all trailers. Do this by waiting for air pressure to build, then sending air to both the emergency and service lines and opening the shut-off valves on the rear of the last trailer. If air escapes from the shut-off valves in the rear of the combination, the air is being supplied to the entire vehicle.

Listening for air at the rear shut-off valve.

Checking for moving air inside of each trailer.

Listening for air at the rear shut-off valve.

Feeling for air at the front shut-off valve.

Making a sudden lane change can be dangerous while driving a combination vehicle. You can avoid the need to make a sudden lange change by looking down the road for upcoming obstacles that will require you to change lanes.

Can help you avoid the need for sudden lane changes.

Is more dangerous than only watching your mirrors.

Does not help you drive more safely.

Can help you avoid the need for sudden lane changes.

Combination Vehicles Practice Test | Michigan 2025 #1 Page 3 of 3

Train for FREE online with our Michigan 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 MI 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 | Michigan 2025 #1 Page 3 of 3

15 . The "crack-the-whip" effect can:

16 . Rollovers happen when:

17 . Place the trailer air supply control in its "emergency" position to test:

18 . The best way to recognize that your trailer has started to skid is by:

19 . Before a trip, you can make sure air flows to all trailers by:

20 . Watching the road ahead:

See the exact questions that will be on the 2025 DMV exam.

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