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It's a practice test that's automatically made up of all your missed questions. Once you finish this test, you’ll be able to revisit your Challenge Bank™ to practice and sharpen your skills.
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Getting a CDL that includes the air brake qualification is essential in Missouri. So many job opportunities are left on the table without the air brake qualification. To obtain it, you’ll need to pass both the Missouri DOR CDL Air Brakes Knowledge Test and the Skills Test in an air brake-equipped vehicle. This will remove the “L” code from your CDL, a restriction that would prohibit you from driving any commercial motor vehicle equipped with air brakes. Failing either test results in a one-day waiting period and a retest fee. You must score a minimum of 80% on the Knowledge Test in order to pass.
Because most Class A and Class B commercial vehicles use air brakes, including semi-trucks, heavy tractors, transit buses, motorcoaches, and large school buses, the “L” restriction definitely limits the jobs you can take. Our Missouri CDL Air Brakes Practice Tests are crafted to help you pass on the first attempt.
Chief Educational Researcher, Driving‑Tests.org (ACES member)
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Our practice tests mirror the official DOR exam format. Test-takers may come across tricky wording, distractors, and double negatives in the official questions, creating confusion during the knowledge test. Our Missouri-specific practice tests introduce these situations ahead of time and are built using the latest Commercial Driver License Manual. Each practice question includes real-time feedback, clear AI-driven explanations, and proven learning techniques that improve retention and speed learning. Our practice materials feature an interactive CDL Manual as well as a Challenge Bank of questions that presents any missed questions again until you’ve answered them correctly. This thorough drill ensures you learn all the practice material before moving on. Try another practice test here: https://driving-tests.org/missouri/mo-cdl-air-brake-practice-test/.
Missouri drivers face conditions along I-44, I-70, I-55, and Route 60, and traffic congestion in St. Louis, Kansas City, Springfield, and Columbia that require precise stopping power and a skilled use of air brakes. The Show-Me State relies heavily on air brake-qualified drivers for industries including agriculture and livestock transport, manufacturing and distribution, logistics and freight, public transit and charter busing, and school district transportation (many full-size school buses require air brakes). Major employers, like Boeing, Ford Kansas City Assembly, General Motors suppliers, Hogan Transportation, Jefferson Lines, Metro Transit, Prime Inc., and YRC Freight, rely on air brake-qualified drivers.
You should also consider adding endorsements to your CDL, such as (N) Tanker, (H) Hazardous Materials, and (T) Doubles/Triples. We have Missouri Practice Tests to help you prepare for these knowledge tests as well: https://driving-tests.org/missouri/mo-cdl-hazmat-practice-test/. You might also check out our Combination Vehicles Practice Tests to prepare for the official combination exam, which is one of the major steps in obtaining a Class A License: https://driving-tests.org/missouri/mo-cdl-combination-test/.
Driver’s Ed is - nobody wants to set foot inside the DOR. That’s why millions of learners trust us for simple, visual, effective prep.
We are an officially recognized FMCSA Entry-Level Driver Training provider and a proud partner to over 2,500 libraries. We work with safety organizations like GHSA and the National Safety Council to help create safer roads for everyone.
Our trademarked system automatically saves questions you miss, creating personalized tests that target your weak spots until you’ve mastered the material.
Get smarter as you study. Our new AI-powered feedback provides detailed, question-level insights to help you understand the why behind each answer.
Go beyond the boring black-and-white manual. Our interactive handbook lets you read, listen with an MP3 audio version, or even chat with it to find the information you need, faster.
We build our practice questions from the current 2025 MO Driver Handbook and refine them using patterns recent test‑takers report.
Driver handbook • Knowledge‑test/permit overview • Fees & ID requirements • Office/appointment info
We mirror recurring themes (e.g., right‑of‑way traps, sign look‑alikes) and use similar distractors and wording styles.
We don’t collect or publish actual test items and we’re not affiliated with DOR.
