Indiana CDL Practice Test — General Knowledge, Air Brakes & Endorsements (2026)
Indiana's CDL knowledge test costs $16, and you must achieve at least 80% to pass. The CDL commercial driver's license fee is $35. Third-party testing providers administer the CDL skills test, with fees of $100 if you use your own vehicle or $175 if you use the testing facility's vehicle. Indiana requires compliance with federal Entry-Level Driver Training (ELDT) regulations.
Sample Indiana CDL Practice Test Questions & Official Manual Citations (2026)
Below are 4 real sample questions from our Indiana cdl practice test bank. Every question in PassMyDMV cites the exact page and rule in the official Indiana manual so you understand the law behind every answer:
Sample Question 1 · Blood Alcohol Content
Official Indiana Manual · Chapter 10 · Page 61
What is Blood Alcohol Content (BAC) and why is it important for drivers?
- A. The type of alcohol being consumed before driving
- B. The amount of alcohol in your blood that impairs driving ability and judgment Correct
- C. The legal limit for driving in all states
- D. A measure of how much food you have eaten
Why B. The amount of alcohol in your blood that impairs driving ability and judgment is correct: Blood Alcohol Content is the amount of alcohol in your blood recorded in milligrams of alcohol per 100 milliliters of blood. BAC depends on the amount of blood (which increases with weight) and how fast you drink. Even small amounts of alcohol impair judgment, reaction time, and driving ability. Understanding BAC effects is critical because alcohol-related crashes are a leading cause of commercial vehicle accidents. [Manual: Pages 61-66 — Blood Alcohol Content, p. 61]
Manual excerpt (Official Indiana Manual · Chapter 10 · Page 61): “Blood Alcohol Content is the amount of alcohol in your blood recorded in milligrams of alcohol per 100 milliliters of blood.”
Sample Question 2 · Air Compressor Governor
Official Indiana Manual · Chapter 12 · Page 73
What is the purpose of the air compressor governor in an air brake system?
- A. Removes water and oil from the brake system
- B. Controls when the compressor pumps air based on tank pressure Correct
- C. Releases air pressure when it exceeds 150 psi
- D. Pumps air into the storage tanks
Why B. Controls when the compressor pumps air based on tank pressure is correct: The air compressor governor controls when the air compressor will pump air into the storage tanks. When air tank pressure rises to the cut-out level (around 125 psi), the governor stops the compressor from pumping. When the tank pressure falls to the cut-in pressure (around 100 psi), the governor allows the compressor to start pumping again. This automatic control maintains proper air pressure for brake operation. [Manual: Pages 73-78 — Air Compressor Governor, p. 73]
Manual excerpt (Official Indiana Manual · Chapter 12 · Page 73): “The governor controls when the air compressor will pump air into the air storage tanks. When air tank pressure rises to the "cut-out" level (around 125 pounds per-square-inch or "psi"), the governor stops the compressor from pumping air. When the tank pressure falls to the "cut-in" pressure (around 100 psi), the governor allows the compressor to start pumping again.”
Sample Question 3 · Air Tank Drains
Official Indiana Manual · Chapter 12 · Page 73
Why must air tanks be drained regularly?
- A. To cool the air before it reaches the brakes
- B. To prevent the governor from cutting in too frequently
- C. To remove water and compressor oil that can damage the brake system Correct
- D. To remove excess pressure above 150 psi
Why C. To remove water and compressor oil that can damage the brake system is correct: Compressed air usually contains water and compressor oil, which can collect in the bottom of air tanks. Water can freeze in cold weather and cause brake failure, while oil damages brake components. Each air tank has a drain valve at the bottom that must be used to completely drain the tanks. You must drain the tanks yourself at the end of each day of driving unless the tanks have automatic drain valves. [Manual: Pages 73-78 — Air Tank Drains, p. 73]
Manual excerpt (Official Indiana Manual · Chapter 12 · Page 73): “Compressed air usually has some water and some compressor oil in it, which is bad for the air brake system. For example, the water can freeze in cold weather and cause brake failure. The water and oil tend to collect in the bottom of the air tank. Be sure that you drain the air tanks completely.”
Sample Question 4 · Brake Systems
Official Indiana Manual · Chapter 12 · Page 73
What are the three different braking systems in an air brake system?
- A. Foot, hand, and spring brakes
- B. Service, parking, and emergency brakes Correct
- C. Primary, secondary, and emergency brakes
- D. Foundation, relay, and supply brakes
Why B. Service, parking, and emergency brakes is correct: Air brakes consist of three different braking systems: the service brake system, parking brake system, and emergency brake system. The service brake system applies and releases the brakes when you use the brake pedal during normal driving. The parking brake system applies and releases the parking brakes when you use the parking brake control. The emergency brake system uses parts of the service and parking brake systems to stop the vehicle in case of a brake system failure. [Manual: Pages 73-78 — Air Brake System Parts, p. 73]
Manual excerpt (Official Indiana Manual · Chapter 12 · Page 73): “Air brakes are really three different braking systems: service brake, parking brake, and emergency brake. The service brake system applies and releases the brakes when you use the brake pedal during normal driving. The parking brake system applies and releases the parking brakes when you use the parking brake control. The emergency brake system uses parts of the service and parking brake systems to stop the vehicle in a brake system failure.”
Most-Tested Indiana CDL Practice Test Topics in Our 615-Question Bank
Our Indiana cdl practice test bank contains 615 active multiple-choice questions written directly from the official Indiana handbook. Here is how those questions break down across the core exam topics:
Frequently Asked Questions: Indiana CDL Practice Test
All Indiana DMV Practice Tests & Study Guides
- Indiana DMV Practice Test Hub (Car, Motorcycle & CDL overview)
- Indiana Car Learner’s Permit Practice Test (817 questions)
- Indiana Motorcycle Permit Practice Test (320 questions)
- Indiana CDL Commercial Practice Test (615 questions)
- Indiana Road Signs & Traffic Signals Practice Test (235 questions)
- Official Indiana Driver Manual Table of Contents & PDF Handbook
- How to Get Your Indiana Driver License: 2026 Step-by-Step Guide
Practice Tests for Other States
- Alabama DMV practice test
- Alaska DMV practice test
- Arizona DMV practice test
- Arkansas DMV practice test
- California DMV practice test
- Colorado DMV practice test
- Connecticut DMV practice test
- Delaware DMV practice test
- Florida DMV practice test
- Georgia DMV practice test
- Hawaii DMV practice test
- Idaho DMV practice test
- Illinois DMV practice test
- Indiana
- Iowa DMV practice test
- Kansas DMV practice test
- Kentucky DMV practice test
- Louisiana DMV practice test
- Maine DMV practice test
- Maryland DMV practice test
- Massachusetts DMV practice test
- Michigan DMV practice test
- Minnesota DMV practice test
- Mississippi DMV practice test
- Missouri DMV practice test
- Montana DMV practice test
- Nebraska DMV practice test
- Nevada DMV practice test
- New Hampshire DMV practice test
- New Jersey DMV practice test
- New Mexico DMV practice test
- New York DMV practice test
- North Carolina DMV practice test
- North Dakota DMV practice test
- Ohio DMV practice test
- Oklahoma DMV practice test
- Oregon DMV practice test
- Pennsylvania DMV practice test
- Rhode Island DMV practice test
- South Carolina DMV practice test
- South Dakota DMV practice test
- Tennessee DMV practice test
- Texas DMV practice test
- Utah DMV practice test
- Vermont DMV practice test
- Virginia DMV practice test
- Washington DMV practice test
- West Virginia DMV practice test
- Wisconsin DMV practice test
- Wyoming DMV practice test