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

Select the vehicle that off-tracks the most.

2 / 40

Select the factor that has no effect on how much liquid you can carry:

3 / 40

Bus drivers must have a commercial driver license if they drive a vehicle designed to seat more than:

4 / 40

A disruptive passenger:

5 / 40

Which of the following are possible causes of tire fires?

6 / 40

You should be in the proper gear before going down a hill because:

7 / 40

In what position should the converter dolly air tank drain valve be in for double trailer combination?

8 / 40

You do not have to stop at railroad crossings, but must slow down and carefully check for other vehicles:

9 / 40

Which of the following must be closed while the bus is in motion?

10 / 40

Which of the following is a necessary qualification for non-bulk packaging?

11 / 40

An example of a low pressure warning signal for air brakes is:

12 / 40

Puddles or dripping fluids from the underside of the transmission and engine may indicate:

13 / 40

The Emergency Response Guide, ERG, can best be explained as _____.

14 / 40

How often should you check the tires on a placarded trailer that has dual tires?

15 / 40

Select the answer that is controlled by the foot brake.

16 / 40

Which seats not securely fastened to the bus are usually allowed?

17 / 40

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

18 / 40

What do you do first during step 3 of starting the engine and inspecting the inside of the cab?

19 / 40

Buses are prohibited from carrying all of the following hazardous materials except:

20 / 40

What placards, if any, do you need if your load includes 20 pounds of Division 2.3 gas and 1,001 pounds of flammable gas?

21 / 40

Which of the following statements is true about speed management?

22 / 40

The sliding mechanism and locking device for a tandem axle on trailers is:

23 / 40

When there is a hazardous materials emergency. You should:

24 / 40

You can be sure air is supplied to the second trailer by:

25 / 40

The trailer height is correct for connecting a converter dolly to a second trailer when:

26 / 40

An "A/W" the first column of the hazardous materials table means:

27 / 40

This carries hydraulic fluid or air to the wheel brake assemby.

28 / 40

Select what you should do before leaving the vehicle unattended:

29 / 40

Select which is not a mandatory emergency equipment:

30 / 40

Remember to_____when steering to avoid a crash while driving doubles.

31 / 40

What do you check when doing a visual inspection of the coupling?

32 / 40

Water is drained from the compressed air tanks because:

33 / 40

A slack adjuster is:

34 / 40

When stopped on a divided highway where should your reflectors be placed?

35 / 40

A commercial motor vehicle (CMV) is defined as:

36 / 40

When backing your vehicle, which of the following is NOT recommended

37 / 40

Secure baggage and freight in ways that avoid damage and:

38 / 40

In safe driving, what does communicating mean?

39 / 40

An oncoming vehicle keeps its high beams on. You should deal with this hazard by:

40 / 40

You must have placards for explosives, poison gas or flammables exceeding:

Your score is

The average score is 47%

5/5 - (2 votes)

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.