CDL Practice Test


Idaho! You will be presented with 40 questions and you must answer 34 questions correctly to pass.  There is a 50 minute time limit.  You may not go back once you answer a question.  Click the "Start Test" button below to begin.  Good luck!

1 / 40

In what position should shut off valves on the rear of the last trailer be in on a set of double trailers?

2 / 40

What is the best way to prevent brakes form overheating while drive down a steep grade?

3 / 40

For emergency braking when driving a double trailer and having to use your brakes to avoid a collision is to:

4 / 40

How often should air tanks be drained?

5 / 40

Mirrors with a convex surface or "spot" mirrors _____.

6 / 40

How many different hazard classes are there?

7 / 40

What are you checking when looking at the lubrication level on a dipstick?

8 / 40

Make sure____when the front trailer supports are up and the trailer is sitting on the tractor.

9 / 40

Select the situation in which you should use the hand valve to park a combination vehicle.

10 / 40

Animals and human foodstuffs should not be loaded in the same vehicle with?

11 / 40

Tires should should be replaced:

12 / 40

What color are all school buses painted?

13 / 40

Which of the following parts do not get checked in the Bus Interior inspection:

14 / 40

Where should you place your warning devices if you must stop on a one-way or divided highway?

15 / 40

Select the true statement in regards to if a glad hand on the blue air line is missing a seal.

16 / 40

This object is not checked at the rear of the trailer.

17 / 40

What should you hear when you have the hand valve on and are testing the trailer brakes by opening the service air line at the back of the trailer?

18 / 40

If students must cross the street, when they get off the bus, which statement is true?

19 / 40

This should be cleaned and then adjusted properly while inside the cab.

20 / 40

You must be alert for road hazards so that:

21 / 40

The most important hand signal you should agree on with a helper is:

22 / 40

You should activate hazard lights within approximately how many feet before railroad crossing?

23 / 40

This gauge has a governor cut-off.

24 / 40

Upon what does the amount of liquid you can carry in a load depend?

25 / 40

Vehicle handling can become unsafe if the weight is not properly balanced. Hard steering can be caused by:

26 / 40

What is most likely to occur when driving double and a set of trailer wheels goes into a skid?

27 / 40

When should you drain air tanks that do not have an automatic tank drain?

28 / 40

Before transporting a sealed load, you must check:

29 / 40

Off-tracking happens when going around a corner and:

30 / 40

Which of the following statements about stopping distances is NOT true?

31 / 40

Select the true statement in regards to empty trucks:

32 / 40

The golden rule for school buses when approaching and crossing railroad tracks is:

33 / 40

The trailer should be lowered so that _____.

34 / 40

Always try to back toward the driver's side because

35 / 40

Do converter dollies have spring brakes?

36 / 40

Select when you should use the parking brake:

37 / 40

Rods, connecting links, and arms from the steering box to the wheel are a part of the:

38 / 40

With most hazardous materials, you may park within 5 feet of the road briefly, if your work requires it. The materials that are the exception and do not allow parking this close to the road are:

39 / 40

Which of the following statements about "Radioactive" labels is true?

40 / 40

What can you do at an accident site to help avoid another accident?

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CDL Category Practice Tests

CDL Practice Test

How To Get A idaho Commercial Drivers License

Applicants can be age 18 or older when applying for their CDL. Those under the age of 21 are not eligible for the Hazmat or Doubles/Triples Endorsement. All applicants must get a DOT medical card to shows their ability to be physically able to drive a commercial motor vehicle.

Any drivers that fall into the following categories are disqualified from receiving their CDL:

  • Having more than one driver’s license.
  • Being convicted of an impaired driving offense in a commercial vehicle within the prior 24 months to submitting the CDL application.
  • Current suspended, revoked, denied, or canceled driver’s license.
  • Having CDL disqualifications in other states.

All applicants are required to complete a practical skills test and knowledge test in order to receive their CDL. Adding endorsements to a CDL will require additional knowledge tests and practical skills tests.

T – Doubles / Triples
P – Passenger
N – Tank Vehicles
H – Hazardous Materials
X – Tank Vehicle That Carries Hazardous Materials

Hit the Open Road

idaho CDL License Test Tips

Applicants for an Idaho CDL must complete a written knowledge test to showcase their retention of the commercial driving laws. Class A drivers are required to take a 70 question assessment that includes 20 questions specifically about combination vehicles. Class B and C applicants are required to pass a 50 question assessment. Those seeking endorsements and removal of the Air Brake Restriction must take additional tests that range between 20 and 30 questions. All tests must be passed with a score of 80 percent or better.

CDL applicants are required to pass a three-part skills test. These parts include a driving test, basic control skills test, and vehicle inspection test. This can be completed at an Idaho State Driving Facility or other approved testing site.

Additional Information

Information on the Idaho Transportation Department

The Idaho Transportation Department administers the CDL requirements and testing in Idaho. To get more information contact them via:


Phone:  208.334.8000


Additional Idaho CDL Helpful Links

Please use the links below to access more valuable Idaho CDL testing resources and to learn more about practice driving tests for the state of Idaho.