The combination CDL test will examine your knowledge of driving combinations, combination vehicle air brakes, antilock brake systems, coupling and uncoupling, and inspecting combinations. In order to receive your combination vehicle endorsement, it is required that you pass the state’s official CDL written Knowledge exam.

Combination Test 01

1 / 30

Large combination vehicles take longer to stop when...?

2 / 30

The emergency air line is usually colored what?

3 / 30

The service air line is controlled by...?

4 / 30

The longer your trailer is, the more the path of your rear wheels will...?

5 / 30

The tractor protection valve will be activated if air pressure falls below...?

6 / 30

If you are using a trailer which does not have spring brakes, you should...?

7 / 30

Jackknifing is more likely to happen when a trailer is...?

8 / 30

Which of these is one of the first things you should do if your vehicle becomes stuck on a railroad crossing?

9 / 30

Truck rollovers are responsible for what percentage of driver deaths in truck crashes?

10 / 30

The most frequent cause of rollover is...?

11 / 30

Ideally, when you have to back up a trailer, you should position your vehicle so you come back...?

12 / 30

The earliest and best way to learn that your trailer has started to skid is...?

13 / 30

If your vehicle gets stuck on a railroad crossing, what should you do?

14 / 30

To regain control of a trailer which is jackknifing, you should...?

15 / 30

When air is let out of the trailer emergency line, what happens?

16 / 30

A rig with triple 27 foot trailers is how much more likely to roll in a crash than a five axle tractor semitrailer of 45 feet?

17 / 30

Which of these will help to prevent rollover?

18 / 30

When pulling a trailer, you should aim to make your steering...?

19 / 30

When backing up with a trailer, you should start the maneuver by turning the steering wheel...?

20 / 30

Which of these vehicles is most likely to get stuck on a railroad crossing?

21 / 30

When making a right-hand turn, you should aim to stop other drivers...?

22 / 30

Your following distance to other vehicles when driving with a trailer should be at least one second for every...?

23 / 30

You should check in your mirrors to see if your trailer is in the correct position every time you...?

24 / 30

The tractor protection valve keeps air in the tractor or truck brake system if...?

25 / 30

You should add at least an extra second to your following distance to other vehicles if you are traveling in excess of...?

26 / 30

You have to make a right turn that can only be completed by using another traffic lane. You should...?

27 / 30

On newer vehicles, the trailer air supply control will be a knob of which color?

28 / 30

In a vehicle with air brakes, the trailer hand valve should only be used for...?

29 / 30

Before reversing a trailer, you should...?

30 / 30

How much more likely is a truck to roll over if it is fully loaded, compared to an empty rig?

Your score is


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