SD CDL Practice Test

The South Dakota Commercial Drivers License knowledge and skills tests are for people seeking a commercial driver license or applicable endorsements. This page brings together free SD CDL practice sets, official test topics, fees, scoring requirements, and retake rules. Use it to choose relevant practice, identify material to revisit in the official manual, and understand the difference between knowledge testing and the driving skills test.

SD CDL Exam at a Glance

What changed for SD CDL in 2026

• Oct 26, 2026: Delivery changed to Knowledge tests at driver exam stations; skills tests at third-party test sites (previously Knowledge tests at DL exam stations; skills test at third-party testers).^[3]
• Oct 26, 2026: Passing score (Knowledge tests) changed to 80% (previously 80% on each test).^[1]
• Oct 26, 2026: Other (update 2026-08-29) changed to South Dakota DPS extended the deadline for K-restricted CDL holders to submit an updated medical certificate to August 29, 2026, with CDL downgrades resuming January 1, 2027. (previously South Dakota DPS extended the deadline for K-restricted CDL holders to submit a valid medical certificate to August 29, 2026; CDL downgrades for missing certificates resume January 1, 2027.).^[6]
• Aug 29, 2026: South Dakota DPS extended the deadline for K-restricted CDL holders to submit an updated medical certificate to August 29, 2026, with CDL downgrades resuming January 1, 2027.^[6]

What the SD CDL is and how it works

According to South Dakota Department of Public Safety, “The General Knowledge Test is required to be taken by all applicants. This test consists of 50 multiple choice questions.”^[1]

The SD CDL testing process assesses commercial driving knowledge and skills. The General Knowledge Test is required for all applicants and contains 50 multiple-choice questions. You must score 80% or better on each knowledge test. The official content areas also cover vehicle systems, specialized operations, Vehicle Inspection, Basic Vehicle Control, and the On-road Test.

Knowledge tests take place at driver exam stations. South Dakota Driver Licensing locations do not administer commercial driving skills tests; those are taken at third-party test sites. The Basic Control Skills Test has a 30-minute limit. That limit applies to that test, not to the entire testing process.

The application fee is $43, with a $20 fee for each endorsement knowledge test administered. The driving skills test costs $150 plus tax. Knowledge tests are given once per day. If you need to retest, return to an exam station the next business day.

Passed knowledge tests and fees remain valid for 6 months. A commercial learner's permit cannot be issued for longer than 1 year. A CDL expires on your birthday in the fifth year after issuance. These are separate validity rules.

For eligibility requirements and which tests apply to your intended driving, consult the South Dakota Department of Public Safety's CDL manual and licensing guidance. Use its driving skills test guidance for delivery details and South Dakota statutes for the application and endorsement fees.

SD CDL content outline and where to practise each area

The content areas below are copied from the official SD CDL content outline published by South Dakota Department of Public Safety. The right-hand column shows which of our practice sets covers it.

Worked examples: how to reason through SD CDL questions

These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.

Example 1

Question: Sample question 4 for Safe Driving Practices & Hazard Awareness?

1. Answer A
2. Answer B
3. Answer C
4. Answer D

Answer: B. Answer B

Explanation:

This placeholder question cannot teach or assess a driving rule. Its answer key labels B as correct, but the stem supplies no driving situation and the options contain no actual actions. There is therefore no factual reason to choose B over A, C, or D, and no basis for explaining why those alternatives are wrong. The existing explanation assumes safety information that the question never provides. Do not use this item to judge your readiness. The rule to remember is that a useful practice explanation must connect a specific situation to a specific rule; an answer letter alone tells you nothing about safe driving.

Example 2

Question: A driver is operating a truck with a dual air brake system. The low air pressure warning light and buzzer activate. What is the most likely pressure range in one of the systems?

1. 80-90 psi
2. 100-120 psi
3. Below 60 psi
4. 20-45 psi

Answer: C. Below 60 psi

Explanation:

The supplied key selects C, but the wording does not establish a unique answer. The accompanying explanation says the warning must activate before pressure drops below 60 psi. That statement does not establish that pressure is already below 60 psi when the warning activates. A and B give higher pressure ranges, but the question supplies no precise activation point with which to evaluate them. D also overlaps C because 20-45 psi is below 60 psi. It therefore cannot be dismissed solely on the pressure range. Remember to distinguish a warning's activation threshold from a pressure reading observed afterward. Check the official air brake material before relying on this item's answer key.

Example 3

Question: A driver is about to begin their pre-trip inspection for the day. Before inspecting any components, what is the very first step they must legally take according to 49 CFR 396.13?

1. Start the engine to build air pressure.
2. Check the oil and coolant levels.
3. Review the previous driver's Driver Vehicle Inspection Report (DVIR).
4. Ensure the vehicle is clean.

Answer: C. Review the previous driver's Driver Vehicle Inspection Report (DVIR).

Explanation:

The supplied key selects C, but its claim about a legally required first step is not established by the verified material here. C concerns reviewing a previous inspection report. A concerns building air pressure, B concerns checking fluids, and D concerns cleanliness. Those differences explain what each option addresses, but they do not establish a legally mandated order. The existing explanation asserts a report-review requirement without showing that it must precede every component inspection. It therefore does not justify rejecting A, B, or D on the question's stated legal basis. Remember to distinguish a required action from a required sequence. Consult the applicable official inspection guidance before using this item as a rule to memorize.

How to use these practice tests

Start with the South Dakota Department of Public Safety's CDL manual. Identify the material relevant to your intended vehicle and endorsements, then use the topic table to choose practice. Where the table has no dedicated set, work directly from the official material.

Begin with Safe Driving Practices & Hazard Awareness and Laws, Endorsements & Regulations. For each missed or uncertain answer, write down the rule you need to check. Read the corresponding manual passage, then explain why the alternatives do not fit before trying related questions again.

Move into relevant vehicle and endorsement sets, such as Air Brake Systems or Tank Vehicle Rules. Use inspection and control questions to identify practical skills that need attention beyond written practice.

Before test day, revisit unresolved topics and check official testing arrangements. Keep the 6-month validity of passed knowledge tests and fees in mind when planning skills testing. These practice questions are written with AI tools and are not real exam questions. If an item is a placeholder or its explanation does not support its answer, return to the official material.

Sources & last verified

1. South Dakota Department of Public Safety — number of questions, time limit, passing score, retake policy (official source). “The General Knowledge Test is required to be taken by all applicants. This test consists of 50 multiple choice questions.” Verified Oct 26, 2026.
2. sdlegislature.gov — exam fee (official source). “The application fee for a commercial driver license is forty-three dollars. For each commercial driver license endorsement knowledge test administered, the fee is twenty dollars.” Verified Oct 26, 2026.
3. South Dakota Department of Public Safety — exam fee, delivery (official source). “The cost of a driving skills test is $150 plus tax.” Verified Oct 26, 2026.
4. sdlegislature.gov — validity (official source). “A commercial driver license issued pursuant to this chapter, expires on the licensee's birthday in the fifth year following the issuance of the license.” Verified Oct 26, 2026.
5. sdlegislature.gov — validity (official source). “No commercial learner's permit may be issued for a period to exceed one year.” Verified Oct 26, 2026.
6. South Dakota Department of Public Safety — other (official source). “However, the Department of Public Safety has extended the deadline for submitting a valid medical certificate to August 29, 2026. No enforcement actions, penalties, or…” Verified Oct 26, 2026.
7. South Dakota Department of Public Safety — other (official source). “air brakes test” Verified Oct 27, 2026.

How we verify: editorial & fact-checking policy. Report an error: contact us.