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

Question 1 of 30

The service air line is controlled by...?

Question 2 of 30

Before reversing a trailer, you should...?

Question 3 of 30

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

Question 4 of 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?

Question 5 of 30

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

Question 6 of 30

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

Question 7 of 30

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

Question 8 of 30

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

Question 9 of 30

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

Question 10 of 30

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

Question 11 of 30

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

Question 12 of 30

The emergency air line is usually colored what?

Question 13 of 30

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

Question 14 of 30

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

Question 15 of 30

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

Question 16 of 30

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

Question 17 of 30

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

Question 18 of 30

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

Question 19 of 30

Which of these will help to prevent rollover?

Question 20 of 30

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

Question 21 of 30

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

Question 22 of 30

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

Question 23 of 30

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

Question 24 of 30

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

Question 25 of 30

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

Question 26 of 30

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

Question 27 of 30

The most frequent cause of rollover is...?

Question 28 of 30

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

Question 29 of 30

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

Question 30 of 30



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