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Your expectations of landing some great driving opportunities may meet with disappointing results if there is an “L” restriction on your South Dakota Commercial Driver’s License (CDL). The “L” restriction does not permit you to drive a vehicle equipped with an air brake system. The vast majority of semi-trucks and full-size buses rely on air brakes to regulate their speed to safely navigate abruptly changing road conditions (i.e., lane closures, sharp curves, and heavy traffic). An extensive knowledge of air brakes allows you to apply the braking force required to slow down or completely stop while transporting heavy loads. Having an air brake restriction places you at risk of missing out on the best driving opportunities. Commercial truck lines and public transportation providers, such as K&J Trucking and Brookings Area Transit, are more likely to hire you based on your ability to safely navigate road conditions using air brakes.
Our South Dakota DMV CDL air brake “endorsement” practice test gives you a leg up in meeting the requirements for removing the “L” restriction from your CDL. It is essential for you to receive adequate training to pass a skills test (including conducting an inspection of the air brakes) and an official Air Brakes Knowledge Test to remove the “L” restriction. The official knowledge test contains 25 questions and requires you to obtain a minimum score of 80% to pass and avoid the one-day waiting period to retest.
M.S., Chief Educational Researcher (ACES member)
Last verified for accuracy on
Using an interactive approach, our South Dakota DMV CDL air brake “endorsement” practice test prepares you to meet the challenges of the official knowledge test. The practice test mimics the format of the official knowledge test. It uses 30 questions to assess your current knowledge level and identify the information you must learn to expand it. You will be provided with a winning game plan based on reliable information.
This South Dakota DMV air brake “endorsement” practice test uses authoritative information to help you develop a firm understanding of air brake operations. The practice test is based on the most recent South Dakota DMV CDL manual (South Dakota CDL Handbook 2025) and is up to date as of December 2025. If you get a question wrong, the practice test takes information directly from the CDL manual to explain the correct answer.
Since the practice test is designed to provide feedback on your performance, you will find traditional study methods much less effective in developing your skills. Traditional study methods are designed to help you memorize the minimum amount of information necessary to pass the official knowledge test and do not provide information to correct your wrong answers. The practice test ensures you have access to the necessary information and know how to apply it to your driving practices so you can pass the official knowledge test on your first try.
Al Swearengen and the Gem Theater hold an infamous place in Old West history, but you can develop reputable driving skills with the practice tests at https://driving-tests.org/south-dakota/.
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 2025 SD 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.
