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Idaho General Knowledge Test

You'll need to handle Idaho's steep grades on Highway 95 and sudden winter storms.

140

Questions

80%

To Pass

Minutes

140 questions · 60 min time limit · 80% to pass

Opens in a practice window — choose your mode inside.

Reviewed by Jack Mahana, CDL Instructor (13+ years)

Last verified: August 2026

All questions sourced from the official Idaho CDL handbook and FMCSA regulations.

About the Idaho General Knowledge Test

Idaho's roads aren't flat. You'll face mountain passes like Lookout Pass and Galena Summit. Winter storms hit hard. You need to know air brakes, cargo securement, and inspection rules. Our test helps you prepare.

Potatoes, timber, and mining drive Idaho's economy. That means heavy loads and special permits. You'll haul through narrow forest roads or icy interstates. Our questions cover real-world Idaho scenarios.

The Idaho CDL General Knowledge test checks your understanding of federal and state regulations. You must score 80% or higher. We pull questions from the Idaho CDL manual. Each one matches the actual exam format.

Practice now to avoid a failed test and wasted time. We explain every answer. You'll learn why a rule matters, not just what it is.

Idaho's commercial driving spans from the high desert of the Snake River Plain to the steep mountain passes of the Bitterroot and Sawtooth Ranges. I-84 and I-86 cross the southern tier, I-15 connects to Montana, and I-90 passes through the panhandle. Our general knowledge practice test mirrors the official Idaho ITD CDL written exam.

The state's mountain passes — including Lookout Pass on I-90 and the grades on US-95 through the central Idaho mountains — demand strong engine-braking skills and winter traction awareness. The Idaho Transportation Department maintains passes through heavy snow, and chain requirements are common in winter. The exam tests grade descent, chain use, and winter driving directly.

Topics Covered

✓Air brakes – critical for heavy trucks on Idaho's mountain descents.

✓Hazardous materials – common in Idaho's agriculture and mining sectors.

✓Cargo securement – chains and straps needed for logging and mining loads.

✓Vehicle inspection – checks required before every trip, especially in winter.

✓Safe driving techniques – braking and shifting on Idaho's steep grades.

✓Accident procedures – Idaho's reporting rules and road closures.

Study Tips

Start with the Idaho CDL manual from the DMV website. Focus on the General Knowledge section first. Then take our practice test repeatedly until you score 90% or higher. Miss a question? Read the explanation and look it up in the manual.

Schedule your DMV appointment early – Idaho testing centers fill up fast. Bring your valid ID and Social Security card. You'll pay a $50 fee for the knowledge test. Use our test to build confidence before you go.

Idaho Specific Information

You can take the Idaho CDL General Knowledge test at any DMV office. Popular locations include Boise, Idaho Falls, Coeur d'Alene, and Twin Falls. Walk-ins aren't always accepted – book online at itd.idaho.gov/dmv/ at least two weeks ahead.
The test is computer-based with 50 multiple-choice questions. You need 40 correct to pass. If you fail, you must wait one day before retaking it. You can take the test three times in a year. After that, you need a 30-day waiting period.
Bring your out-of-state CDL manual if you're transferring. Idaho honors valid CDLs from other states. But you still pass the General Knowledge test unless you have a valid interstate CDL with no restrictions.
The Idaho Transportation Department (ITD) requires a knowledge test for all CDL classes; the general knowledge exam is the foundation for every commercial license.
Lookout Pass on I-90 and the grades on US-95 through central Idaho require low-gear descents and winter chain use.
The Snake River Plain's long, straight highways invite fatigue — the exam covers hours-of-service and fatigue management.
Idaho's agricultural industry (potatoes, sugar beets, dairy) generates heavy seasonal hauls on rural highways.
Winter conditions can close mountain passes; the exam tests chain requirements and winter driving awareness.

Frequently Asked Questions

Do I need a CDL to drive a farm truck in Idaho?

It depends. If you transport your own farm products within 150 miles and don't cross state lines, you may use a farm waiver. But if you haul hazardous materials or drive a tanker, you still need a CDL.

How do I schedule my Idaho CDL skills test?

You schedule through the third-party testing center near you (like in Boise or Idaho Falls). The DMV doesn't do skills tests directly. Find an approved tester on the ITD website.

What's the minimum age for an interstate CDL in Idaho?

21. For intrastate only (staying inside Idaho), you can get a CDL at 18. But you can't carry hazardous materials that require a hazmat endorsement until 21.

Can I take the Idaho CDL knowledge test online?

No. You must take it in person at a DMV office. You can't do it from home. Bring your ID and pay the fee.

What happens if I fail the General Knowledge test three times?

You must wait 30 days after the third failure before you can try again. Use that time to study and take our practice tests. You'll pass the fourth time.

Reviewed by Jack Mahana, CDL Instructor (13+ years)

Last verified: August 2026 · FMCSA-compliant content