Idaho CDL Practice Test

Correct answer: A (K) restriction — commercial driving within Idaho only (intrastate)

Idaho issues CDLs at age 18, but a (K) intrastate restriction is placed on all 18-, 19-, and 20-year-old CDL holders and on anyone who plans to drive commercially only in Idaho. Interstate CMV operation requires you to be at least 21 (49 CFR 391.11).

Correct answer: $29.00

The Idaho CDL fee schedule lists the Commercial Learner’s Permit at $29.00. You must already hold an Idaho driver license to be issued a CLP.

Correct answer: $5.00 each

Idaho’s fee schedule charges $5.00 for each written test. If you have to retake a section you did not pass, you pay the $5.00 written-test fee again.

Correct answer: One year from the date they were passed

All Idaho CDL test results remain valid for one year from the date they were passed. You must complete the remaining tests and be licensed within that year, or you will have to retest.

Correct answer: 50 questions — 40 correct to pass

Idaho’s "Knowledge Test Information" table lists the General Knowledge test at 50 questions with a minimum of 40 correct to pass — the federal 80% pass mark. (Air Brakes is 25/20 and Combination Vehicles is 20/16.)

Correct answer: Non-excepted interstate

Idaho requires you to self-certify into one of four categories: non-excepted interstate, excepted interstate, non-excepted intrastate, or excepted intrastate. Non-excepted drivers must keep a current medical examiner’s certificate on file. You can self-certify at a county office or on the ITD website.

Correct answer: You are placed out-of-service for 24 hours

A BAC of .04% or higher disqualifies you, but any detectable amount of alcohol below .04% still puts you out-of-service for 24 hours. Operating a CMV also means you have given consent to alcohol testing.

Correct answer: One year — three years if the CMV was placarded for hazardous materials

A first major offense — including a .04% BAC, refusing a test, or leaving the scene of a CMV accident — disqualifies you for at least one year, or three years if you were hauling placarded hazardous materials. A second major offense is a lifetime disqualification.

Correct answer: Only twice in a lifetime

Idaho offers a Seasonal CDL for certain farm-related service industries. It is valid (with a Class D license) for 180 days in a 12-month period and can be obtained only twice in a lifetime.

Correct answer: At least 16 years old, with a valid Class D license

A Seasonal CDL applicant must be at least 16 years of age, hold a valid Class D license, and have at least one year of driving experience with a clean disqualification-free record.

Correct answer: Perception distance + reaction distance + braking distance

Total stopping distance = perception distance + reaction distance + braking distance. It is the total minimum distance your vehicle travels from the moment you see a hazard until you can bring the vehicle to a complete stop.

Correct answer: The distance your vehicle travels from when your eyes see a hazard until your brain recognizes it

Perception distance is how far your vehicle travels, in ideal conditions, from the time your eyes see a hazard until your brain recognizes it. It can be affected by mental and physical condition, visibility, and the hazard itself.

Correct answer: About 1¾ seconds

The average perception time for an alert driver is 1¾ seconds. At 55 mph that accounts for about 142 feet traveled before your brain even recognizes the hazard.

Correct answer: About 142 feet

At 55 mph, the 1¾-second average perception time accounts for about 142 feet traveled — the distance covered before your brain recognizes the hazard.

Correct answer: The distance you travel before you physically hit the brakes, after seeing a hazard

Reaction distance is how far you keep traveling, in ideal conditions, before you physically hit the brakes in response to a hazard already seen. The average driver has a reaction time of ¾ second to 1 second.

Correct answer: About 61 feet

The average driver has a reaction time of ¾ to 1 second. At 55 mph that accounts for about 61 feet traveled before the brakes are actually applied.

Correct answer: About 216 feet

Braking distance is how far the vehicle travels while you are braking. At 55 mph on dry pavement with good brakes, it can take about 216 feet.

Correct answer: About 419 feet

Adding perception (142 ft), reaction (61 ft), and braking (216 ft) distance at 55 mph gives a minimum total stopping distance of about 419 feet — greater than the length of a football field.

Correct answer: 4 times longer

When you double your speed from 20 to 40 mph, the impact and the braking distance are about 4 times greater. Speed has a huge effect on both stopping distance and crash severity.

Correct answer: 9 times greater

Triple the speed from 20 to 60 mph and the impact and braking distance are about 9 times greater. At 80 mph they are 16 times greater than at 20 mph.