Free, full South Dakota CDL general knowledge test practice right here in your browser — real exam format (50 questions, 80% to pass), diagnostic and adaptive modes, spaced-repetition review, and a readiness dashboard. No signup, no paywall — your progress is saved automatically on this device. Matched to the official DPS knowledge exam.
CDL safety scenario 51: If the low air pressure warning activates while driving a commercial vehicle, what should you do?
B. Stop safely as soon as possible — Stop safely as soon as possible. Commercial drivers are expected to manage this situation before it becomes a crash risk. The CDL manual emphasizes controlling the vehicle, inspecting safety-critical systems, and correcting hazards promptly.
What does a 'blue tag' placed on a commercial vehicle at a weigh station typically indicate?
B. The vehicle has been selected for a more detailed Level II or Level III inspection at a later facility — A blue tag (or similar colored tag in various states) placed on a vehicle during a weigh station stop typically indicates the vehicle has been flagged for a secondary, more thorough inspection at the next enforcement station it passes.
CDL safety scenario 27: If the low air pressure warning activates while driving a commercial vehicle, what should you do?
B. Stop safely as soon as possible — Stop safely as soon as possible. Commercial drivers are expected to manage this situation before it becomes a crash risk. The CDL manual emphasizes controlling the vehicle, inspecting safety-critical systems, and correcting hazards promptly.
When transporting hazmat, placards must be placed:
D. On all four sides of the vehicle — Placards must be displayed on all four sides of the vehicle (front, rear, and both sides) so they're visible from any direction.
If your commercial vehicle begins to hydroplane, you should:
C. Release the accelerator and push in the clutch, keeping the wheel steady until traction returns — Easing off the throttle and clutching lets the tires slow and regain contact, while braking or hard steering can cause a skid.
Under the 60/70-hour rule, a property-carrying driver on a 7-consecutive-day schedule may drive a maximum of how many hours in 7 days?
D. 60 hours in 7 days — Drivers using a 7-day schedule may not drive after accumulating 60 on-duty hours in 7 consecutive days. Drivers on 8-day schedules use the 70-hour/8-day rule.
What should you do if you discover a coupling problem (e.g., a cracked fifth wheel plate) during a pre-trip inspection?
B. Do not drive — report the defect to your supervisor and do not operate the vehicle until repairs are made — A defective fifth wheel plate is a critical safety defect. You must not operate the vehicle with a defective coupling device. Report it immediately and wait for repairs before operating.
Hazmat Class 3 covers:
C. Flammable liquids — Hazmat Class 3 covers flammable liquids — substances that ignite easily at or below 140°F (60°C). Examples include gasoline, diesel fuel, ethanol, and paint thinner. Class 3 materials require a red FLAMMABLE placard and specific handling and parking rules.
What is the 'crack-the-whip' effect in doubles and triples combinations?
B. The amplified sway of each successive trailer — the last trailer sways much more than the one ahead of it — Like a whip, each trailer in a doubles/triples combination moves more than the one ahead during a lane change or swerve. The last trailer can sway several times the amount of the tractor's steering input.
Using the trailer hand valve (trolley valve) to hold a vehicle on a hill is:
D. A bad practice, because the trailer brakes alone may not hold and can overheat — The hand valve should not be used for parking; the parking brakes hold the whole vehicle, while trailer brakes alone may slip or overheat.
The South Dakota CDL general knowledge test has 50 questions, and you need 80% to pass — at least 40 correct answers. The practice tests on this page use the same format. The 80% passing score is a federal FMCSA standard used by every state.
80%. You can miss at most 10 of the 50 questions. The readiness dashboard on this page tracks whether you're consistently scoring above that bar.
In South Dakota, driver licensing is handled by the Department of Public Safety (DPS), so you'll often see the exam called the DPS CDL general knowledge test. The practice tests on this page match the official DPS knowledge exam format.
Yes. Every practice test on this page and everything in the DMVPrep iPhone app is free — no ads, no paywall, no account.
Federal motor carrier safety regulations (FMCSA) — the same rules every state's CDL exam is drawn from. Every question in the DMVPrep app cites the regulation or handbook section it comes from.
Yes — the DMVPrep app includes all 3,745+ questions in Spanish, and the whole app works in Spanish.