Pass your CDL permit test on the first try
215 practice questions for the CDL knowledge tests, each with a plain-English explanation. Take practice tests for General Knowledge, Air Brakes, Combination Vehicles and Hazmat, scored like the real ones.
Practice by section
Everyone takes General Knowledge. Most Class A drivers also take Air Brakes and Combination Vehicles, and the H endorsement adds Hazardous Materials. The question counts below are typical; your state's may differ slightly.
General Knowledge 84 questions
CDL classes, endorsements and disqualifications, alcohol rules, vehicle inspection, following distance and space management, speed and stopping distance, night, winter and mountain driving, railroad crossings, skids and emergencies, accidents and fires, and cargo weight and securement.
Air Brakes 38 questions
How air brakes work, governor and tank pressures, spring and parking brakes, dual air systems, the air brake inspection (slack adjusters, leakage, low air warning, spring brake and buildup tests), brake lag and stopping distance, and braking on downgrades.
Combination Vehicles 39 questions
Rollover and rearward amplification, trailer skids and jackknifes, off-tracking and backing, trailer air lines, glad hands and controls, trailer ABS, coupling and uncoupling, inspecting the fifth wheel and the combination brake checks.
Hazardous Materials 54 questions
The nine hazard classes, shipping papers and the Hazardous Materials Table, placarding (Table 1, Table 2, DANGEROUS), loading and unloading by class, cargo tanks, parking and attending, routes, railroad crossings, and leaks, fires and crashes.
What full access includes
- All 215 questions for General Knowledge, Air Brakes, Combination Vehicles and Hazmat
- An explanation for every answer, from the CDL manual and federal rules
- Unlimited practice tests for each knowledge test, scored like the real one (80% to pass)
- A review of every question you missed at the end of each test
- Works on your phone, tablet or computer, with no app or account
Full access
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About the CDL exam
Which tests do I need?
Everyone takes General Knowledge. For a Class A CDL you will usually also take Air Brakes (unless you accept an air brake restriction) and Combination Vehicles. Endorsements add their own tests, such as Hazardous Materials for the H endorsement.
How many questions are on the tests?
It depends on your state. General Knowledge usually has 50 questions, Air Brakes 25, Combination Vehicles 20 and Hazardous Materials 30. Most states require 80% to pass each test.
What happens after I pass?
You get a commercial learner's permit (CLP). Federal rules require you to hold it for at least 14 days before taking the skills test, and first-time Class A and B applicants must complete entry-level driver training with a provider on FMCSA's Training Provider Registry before the skills test. For the H endorsement, the hazmat training must be finished before you take the Hazardous Materials knowledge test.
Is this the official test?
No. This is practice material based on the model CDL manual most states use and on federal regulations. The real tests are given by your state's driver licensing agency, so also read your state's CDL manual for state-specific rules.