All your missed questions are saved
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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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View All Plans| 90-100 | => | 14% |
| 80-89 | => | 29% |
| 70-79 | => | 57% |
| 60-69 | => | 0% |
| <60% | => | 0% |
If you’re planning to drive commercial motor vehicles (CMVs) equipped with air brakes in Colorado, you’ll need to pass the Colorado DMV CDL Air Brakes Knowledge Test. Failing to do so means your CDL will carry an “L” restriction, barring you from operating CMVs with air brakes. This is a significant limitation since nearly all semi-trucks and tractor-trailers rely on air brakes. From the driving challenges of the Rocky Mountains to major highways like I-70 and US-550 (the famed Million Dollar Highway), hauling freight through the Eisenhower Tunnel or navigating the Front Range, air brakes help to keep you and everyone else safe on the road.
To remove the “L” restriction, you must complete both a written knowledge test and a skills test. The Knowledge Test covers system components, brake operation, and inspection procedures and requires a minimum score of 80% to pass. The Skills Test is conducted in a vehicle equipped with air brakes. You’ll perform hands-on inspections, identify system parts, and demonstrate leak and pressure checks. Failing to take the skills test in a vehicle with air brakes results in the restriction being added automatically.
M.S., Chief Educational Researcher (ACES member)
Last verified for accuracy on
To make sure you’re ready, our Colorado CDL Air Brakes Practice Tests mirror the format of the official exam, providing immediate feedback so you can learn faster and retain more information. Our experts have also eliminated the fluff that is not tested so you can focus on what counts. We offer an interactive handbook as well as AI-powered feedback, and a Challenge Bank of questions that remembers what you missed and reintroduces those questions until you have them mastered. Once you have a handle on this practice test, try another one here: https://driving-tests.org/colorado/co-cdl-air-brake-practice-test/.
Top employers like FedEx Freight, J.B. Hunt, Old Dominion, Schneider National, Swift Transportation, and Werner Enterprises look for Colorado CDL drivers with the air brakes qualification. So, get prepared! While you’re at it, check out our Endorsement Practice Tests to add valuable certifications to your CDL. See one of them here: https://driving-tests.org/colorado/co-cdl-hazmat-practice-test/. You may also want to obtain a Class A CDL, which enables you to legally transport freight in tractor-trailers and other combination vehicles. We have materials to help you ace those tests as well: https://driving-tests.org/colorado/co-cdl-combination-test/.
What are you waiting for? Our series of Colorado practice tests is your key to career advancement!
Driver’s Ed is - nobody wants to set foot inside the DMV. 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 2026 CO 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 DMV.
