The CDL doubles and triples endorsement test will examine your knowledge of pulling double/triple trailers, coupling and uncoupling, inspecting doubles and triples, and checking air brakes. In order to receive your Doubles and Triples endorsement, it is required that you pass the state’s official CDL written Knowledge exam.
Converter dollies will have antilock brakes if they were built on or after March 1...?

Question 1 of 30

If you are coupling your second trailer and it doesn't have spring brakes, you can apply the emergency brakes by...?

Question 2 of 30

When taking a curve in a double/triple combination, you should slow down to a safe speed before entering, then during the curve you should...?

Question 3 of 30

If you have any doubts about the brakes on your second trailer when connecting, you should...?

Question 4 of 30

The most important thing to do if your vehicle starts skidding is to...?

Question 5 of 30

When inspecting a double/triple combination, you should give special attention to...?

Question 6 of 30

When driving a double/triple combination, you need to plan far ahead so that you can keep your driving...?

Question 7 of 30

A converter gear on a dolly is...?

Question 8 of 30

A converter dolly equipped with antilock brakes will have a yellow lamp...?

Question 9 of 30

When making a lane change in a double/triple combination, you must check your mirrors...?

Question 10 of 30

In a combination vehicle on slippery roads, you should not use...?

Question 11 of 30

When driving a double/triple combination which is 90 feet long at 30 mph, how much following distance should you allow?

Question 12 of 30

When parking a double/triple combination, you should arrange things so that you can...?

Question 13 of 30

If your speed doubles, your stopping distance increases...?

Question 14 of 30

Corners when driving a double/triple should be taken...?

Question 15 of 30

If a converter dolly has air brakes, you should release them by...?

Question 16 of 30

In a double/triple combination, which of these is the most likely to turn over?

Question 17 of 30

In which of these environments should you be especially cautious about tipping over a double/triple?

Question 18 of 30

Compared to other commercial vehicles, doubles/triples have...?

Question 19 of 30

Compared to smaller commercial vehicles, double/triple combinations need more...?

Question 20 of 30

With a double/triple combination, which of these will take longer to stop?

Question 21 of 30

In comparison with other commercial vehicles, doubles/triples are...?

Question 22 of 30

When driving a double/triple, to prevent rollover you must steer...?

Question 23 of 30

For the safest handling on the road, your most heavily loaded trailer should go...?

Question 24 of 30

You are driving a 110 foot long combination vehicle at 55 mph. What should your following distance be?

Question 25 of 30

On converter dollies with spring brakes, you should release them with...?

Question 26 of 30

When driving a double/triple combination, you should avoid changing lanes near...?

Question 27 of 30

On long downgrades, your trailer brakes should be used...?

Question 28 of 30

When driving a double/triple combination, compared to a straight truck or single, your following distance should be...?

Question 29 of 30

Why are double/triple combinations more likely to skid in adverse conditions?

Question 30 of 30



Studying and applying oneself is the only way to successfully learn the information you need to know to pass all testing required to obtain your CDL. We are here to help.

Don’t hesitate to take advantage of our practice tests in each category specific to your needs. We wish you the best of luck in your endeavors and are pleased to be of assistance.


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