Free South Dakota DMV CDL — General Knowledge Practice Test 2026
The South Dakota CDL — General Knowledge knowledge test has ~50 questions, and you need ~40 correct (80%) to pass. Practice free with questions written from the official South Dakota driver handbook — every one has a clear explanation, and you can retake as often as you like with no sign-up.
Content reviewed against official driver handbooks · August 12, 2026
What's on the South Dakota written test
The South Dakota CDL — General Knowledge knowledge test has ~50 questions; you need ~40 correct (80%) to pass.
Based on the official South Dakota exam format — always confirm current details with your state DMV.
Practice by topic
Focus on one area at a time — each topic has its own set of South Dakota practice questions.
Learn the shapes, colors, and meanings of regulatory, warning, and guide signs — from stop and yield to construction and school-zone signs.
Speed limits, turning and signaling rules, headlight and seat-belt requirements, and the everyday laws every driver must follow.
How to read traffic signals, lane lines, and pavement markings — including yellow and white lines, arrows, and flashing lights.
Who goes first at intersections, four-way stops, roundabouts, and crosswalks, and how to yield to pedestrians and emergency vehicles.
Following distance, scanning, blind spots, using your lights, and the habits that prevent crashes and keep you in control.
Driving safely around motorcycles, bicycles, large trucks, pedestrians, and school buses — and knowing who has the right of way.
Blood alcohol limits, zero-tolerance and implied-consent laws, and how alcohol and drugs — legal or not — affect your driving.
Legal and illegal parking, colored curbs, distances from hydrants and crossings, and how to park safely on hills.
Choosing a safe speed, keeping a space cushion, adjusting for weather and traffic, and understanding stopping distance.
What to do when things go wrong — brake failure, tire blowouts, skids, and stalling on railroad tracks.
The point system, license suspension, provisional-license rules, insurance requirements, and other licensing basics.
How to pass the first time
- Read the official South Dakota driver handbook at least once before test day.
- Practice by topic to find your weak spots, then fix them.
- Take full-length practice tests until you pass comfortably every time.
- Read every explanation — understanding beats memorizing.
South Dakota CDL — General Knowledge test — frequently asked questions
How many questions are on the South Dakota CDL — General Knowledge test?
The South Dakota CDL — General Knowledge knowledge test has ~50 questions, and you need ~40 correct (80%) to pass. Our practice tests mirror that format.
How many questions can I miss on the South Dakota CDL — General Knowledge test?
You can miss up to ~10 of the ~50 questions and still pass — you need ~40 correct, which is 80%.
Can I retake the practice test?
Yes — practice as often as you like, completely free. The questions and answer choices are shuffled each time.
Can I take the South Dakota practice test in Spanish?
Yes. Every question here is available in English and Spanish — switch languages anytime. Many states also offer the real knowledge test in languages other than English; confirm what South Dakota offers with your DMV.
Can I practice on my phone?
Yes. The practice tests work in any mobile or desktop browser — no app or sign-up needed — so you can study anywhere.
Are these the real DMV test questions?
No. Our questions are original, written from the current official South Dakota driver handbook to match the real test's topics and style. We are not affiliated with any DMV or government agency.
What's the best way to study?
Read the South Dakota driver handbook, practice by topic to target weak areas, and finish with full-length tests until you consistently pass.
Other South Dakota practice tests
Take the CDL — General Knowledge test in another state
Every South Dakota question is written from the official South Dakota driver handbook and checked against its current edition. DMV Test Free is a free, independent study resource — not affiliated with any DMV or government agency. About DMV Test Free
South Dakota CDL — General Knowledge questions with answers
20 sample questions from the South Dakota CDL — General Knowledge question bank — each with the correct answer, a short explanation, and the section of the official handbook it comes from.
Show all 20 questions with answers
1. What do wet roads do to stopping distance, according to the manual?
Correct answer: They can double it
A slippery road takes longer to stop on, and the manual says wet roads can double stopping distance. A driver has to go slower to stop in the same space as on a dry road.
Source: South Dakota Commercial Driver License Manual — Section 2.6.2, Matching Speed to the Road Surface
2. The Federal Motor Carrier Safety Administration notifies South Dakota that a CDL holder is an imminent hazard. What does the state do?
Correct answer: Disqualifies the driver's CDL
Under the Imminent Hazardous Disqualification entry, a notification from FMCSA that a driver is an imminent hazard results in the CDL being disqualified.
Source: South Dakota Commercial Driver License Manual — CDL Disqualifications, Imminent Hazardous Disqualification
3. Besides slowing the vehicle, what benefits does the manual give for retarders?
Correct answer: Less wear on the brakes, plus one more means of slowing the vehicle
Retarders help slow a vehicle and cut down the need for the brakes. That reduces brake wear and gives the driver another way to slow down, though they should be switched off on slippery roads.
Source: South Dakota Commercial Driver License Manual — Section 2.3.4, Retarders
4. According to the manual, how does tying state-issued CDL privileges to a driver's Clearinghouse status add a layer of safety?
Correct answer: It is harder to hide violations from employers
Because a driver with a prohibited status loses or is denied commercial privileges, it becomes more difficult to conceal a drug and alcohol program violation from an employer and to evade the ban on driving a CMV.
Source: South Dakota Commercial Driver License Manual — Clearinghouse-II and CDL Downgrades
5. A South Dakota driver needs an SR22 on file to show future financial responsibility. How must the form reach the Driver Licensing Program?
Correct answer: Directly from the insurance company to the central administrative office
Most motorists meet the requirement by having their insurer file an SR22. The form has to come straight from the insurance company and be received at the central administrative office, because driver exam stations cannot accept SR22 forms.
Source: South Dakota Commercial Driver License Manual — General Information, Financial Responsibility
6. For a South Dakota Seasonal CDL holder, what capacity limit applies to vehicles or implements of husbandry hauling liquid fertilizer?
Correct answer: A total capacity of 3,000 gallons or less
Liquid fertilizers such as plant nutrients may be hauled on a Seasonal CDL when the vehicle or implement of husbandry has a total capacity of no more than 3,000 gallons. The 1,000-gallon figure belongs to diesel fuel.
Source: South Dakota Commercial Driver License Manual — General Information, Seasonal Farm-Services CDL
7. What does the manual advise about eye contact with an aggressive driver?
Correct answer: Avoid it
The advice is simply to avoid eye contact. Drivers are also told not to react to gestures, and to ignore them.
Source: South Dakota Commercial Driver License Manual — Section 2.10.3, What You Should Do When Confronted by an Aggressive Driver
8. A heavy thumping or vibration starts while you drive. What may it mean, and for which tire might it be the only sign?
Correct answer: A tire has gone flat; with a rear tire it may be the only sign you get
Vibration is one of the major signs of tire failure, along with sound and feel. Heavy thumping can mean a flat, and when the flat is a rear tire there may be no other warning.
Source: South Dakota Commercial Driver License Manual — Section 2.17.4, Tire Failure
9. In very hot weather you stop and find a tire too hot to touch. What should you do?
Correct answer: Stay stopped until the tire cools off
A tire that is too hot to touch may blow out or catch fire if the trip continues. The manual says to remain stopped until it has cooled.
Source: South Dakota Commercial Driver License Manual — Section 2.14.1, Vehicle Checks
10. On the CDL road test, when does the lane usage standard accept your not being in the right-most lane?
Correct answer: When that lane is blocked
The lane usage standard says to move to, or stay in, the right-most lane unless the lane is blocked. It also calls for a right turn to end in the curb lane, the one farthest right.
Source: South Dakota Commercial Driver License Manual — Section 13.1.14(d), Lane Usage
11. In the Forward Offset Tracking exercise, what must stay between the cone and the line as you drive through?
Correct answer: The right-most rear tire
You steer to the left, through the opening and into the other lane, and the rear tire farthest to the right has to stay between the cone and the line the whole way, with no stopping. That clearance is one of the things scored.
Source: South Dakota Commercial Driver License Manual — Section 12.2.3, Exercise 3 – Forward Offset Tracking
12. At 55 mph on dry pavement, which part of total stopping distance is the longest, by the manual's figures?
Correct answer: Braking distance, at about 216 feet
The manual's figures at 55 mph are 142 feet for perception, 61 feet for reaction, and about 216 feet for braking with good brakes on dry pavement. Braking is the largest share.
Source: South Dakota Commercial Driver License Manual — Section 2.6.1, Stopping Distance
13. A South Dakota driver was reinstated after serving 10 years of a lifetime disqualification, then is convicted of another major offense. What is the result?
Correct answer: A permanent lifetime disqualification
The manual lists an additional major offense after reinstatement of a 10-year disqualification as grounds for a permanent lifetime disqualification, citing SDCL 32-12A-39.
Source: South Dakota Commercial Driver License Manual — CDL Disqualifications, Permanent Lifetime Disqualification
14. When you are pulling a trailer, what can rough acceleration damage?
Correct answer: The coupling
The manual says acceleration should be smooth and gradual, without jerking. Rough acceleration can cause mechanical damage, and with a trailer it can damage the coupling.
Source: South Dakota Commercial Driver License Manual — Section 2.2.1, Accelerating
15. Which of these is a major traffic violation on South Dakota's list even when it happens in a non-commercial vehicle?
Correct answer: DUI at .08 or above
The list's DUI entry, at .08 or above, covers commercial and non-commercial motor vehicles alike. The lower .04 to .079 BAC entry applies to driving a CMV, and speeding and following too closely are serious, not major, violations.
Source: South Dakota Commercial Driver License Manual — CDL Disqualifications, Major Traffic Violations
16. You bring a vehicle into South Dakota from another state. How long do you have to register it, and with whom?
Correct answer: 90 days, with the County Treasurer of your county of residence
Vehicles owned by South Dakota residents and driven on public highways are registered with the County Treasurer where the owner lives. A vehicle brought in from another state must be registered within 90 days.
Source: South Dakota Commercial Driver License Manual — General Information, Vehicle Registration and Titles
17. Pavement markings ahead of a railroad crossing carry the same meaning as the advance warning sign. What do they consist of?
Correct answer: An 'X' with 'RR', and on two-lane roads a no-passing marking
The markings are an 'X' with the letters 'RR.' On two-lane roads a no-passing marking goes with them.
Source: South Dakota Commercial Driver License Manual — Section 2.15.2, Warning Signs and Devices
18. The manual lists vehicles that are slow by their nature. Which of these is NOT on that list?
Correct answer: Motorcycles
The examples of slow vehicles are mopeds, farm machinery, construction machinery, and tractors. Seeing one of them early is a hazard clue that can prevent a crash.
Source: South Dakota Commercial Driver License Manual — Section 2.8.3, Drivers Who Are Hazards
19. As a fire-prevention step, what should you check for whenever you stop during a trip?
Correct answer: Signs of heat in the tires, wheels, and truck body
The en route inspection in the Fire Prevention list looks for signs of heat in three places at every stop: tires, wheels, and the truck body.
Source: South Dakota Commercial Driver License Manual — Section 2.21.2, Fire Prevention
20. You stop to help at an accident scene. Where should you park, and why?
Correct answer: Away from it; emergency vehicles will need the area around it
A driver stopping to help should park clear of the accident. Emergency vehicles will need the space immediately around it.
Source: South Dakota Commercial Driver License Manual — Section 2.20.1, Protect the Area