South Dakota CDL — General Knowledge practice
South Dakota CDL — General Knowledge: Alcohol & Drugs practice test
Blood alcohol limits, zero-tolerance and implied-consent laws, and how alcohol and drugs — legal or not — affect your driving.
Content reviewed against official driver handbooks · August 12, 2026
15 questions · pass with 12 correct. You get instant feedback and an explanation after every answer.
Study questions with answers
12 sample Alcohol & Drugs questions with the correct answer, a short explanation, and the official handbook reference. Read through them, then take the quiz above.
Show all 12 questions with answers
1. Which of these contains the same amount of alcohol as a 12-ounce glass of 5% beer, according to the manual?
Correct answer: One and a half ounces of 80 proof liquor
The manual treats three drinks as equal in alcohol: 12 ounces of 5% beer, 5 ounces of 12% wine, and one and a half ounces of 80 proof liquor.
Source: South Dakota Commercial Driver License Manual — Section 2.22.1, Alcohol and Driving
2. A driver has a drug and alcohol program violation recorded in the Clearinghouse. What must be completed before that driver can operate CMVs on public roads again?
Correct answer: The return-to-duty process
A prohibited driver stays off the road until the return-to-duty process is finished. The manual says this means working with a professional to receive and complete the evaluation, treatment, and testing that are required.
Source: South Dakota Commercial Driver License Manual — Clearinghouse-II and CDL Downgrades
3. A South Dakota driver refuses a chemical test. Besides a disqualification of at least one year, what happens right away?
Correct answer: The driver is placed out of service for 24 hours
On top of the disqualification of at least one year, a driver who refuses the chemical test is immediately put out of service for a 24-hour period. The manual cites SDCL 32-12A-43 together with 32-12A-46.
Source: South Dakota Commercial Driver License Manual — General Information, Refusal of the Chemical Test
4. Under South Dakota's implied consent rule for commercial drivers, what act counts as giving consent to chemical testing?
Correct answer: Driving a commercial vehicle on any public road in South Dakota
Consent is automatic. Driving a commercial vehicle on South Dakota's public roads means agreeing to a blood, breath, or urine test for alcohol and/or drug concentration.
Source: South Dakota Commercial Driver License Manual — General Information, Implied Consent to alcohol testing
5. The manual lists abilities that alcohol impairs. Which of these is NOT on that list?
Correct answer: Hearing
Alcohol is said to impair four things: coordination of the muscles, reaction time, perception of depth, and vision at night. It also affects the brain's control of judgment and inhibition. Hearing is not mentioned.
Source: South Dakota Commercial Driver License Manual — Section 2.22.1, Alcohol and Driving
6. A South Dakota CDL holder is stopped in a personal car and refuses the chemical test. Does the state's CDL disqualification for refusal apply?
Correct answer: Yes; a refusal in either kind of vehicle brings at least a one-year disqualification
The Refusal of the Chemical Test section covers refusals made while driving either kind of vehicle. The list of major traffic violations likewise includes a chemical test refusal in either a commercial or a non-commercial motor vehicle.
Source: South Dakota Commercial Driver License Manual — General Information, Refusal of the Chemical Test
7. A CMV driver is found with a detectable amount of alcohol that is under .04%. What does Section 1 of the manual say happens?
Correct answer: The driver is put out of service for 24 hours
A BAC of .04% or more costs a driver the CDL for at least a year. Any detectable amount below that level still results in being put out of service for 24 hours.
Source: South Dakota Commercial Driver License Manual — Section 1.3.2, Alcohol, Leaving the Scene of an Accident, and Commission of a Felony
8. The 'Are You At Risk?' list warns about taking sedating medications. Which examples does it give?
Correct answer: Antidepressants, cold tablets, and antihistamines
Among the drowsy-driving risk factors, the list names sedating medications and gives antidepressants, cold tablets, and antihistamines as examples.
Source: South Dakota Commercial Driver License Manual — Section 2.11.2, Driver Factors
9. On the manual's Approximate Blood Alcohol Content chart, about what BAC does a 140-pound person reach after three drinks, before subtracting anything for time?
Correct answer: .08
The three-drink row reads .11 at 100 pounds, .09 at 120 pounds, and .08 at 140 pounds. The chart then has you take off .01% for every 40 minutes spent drinking.
Source: South Dakota Commercial Driver License Manual — Section 2.22.1, Alcohol and Driving
10. At which level does the manual's table of BAC effects say most people lose consciousness and some die?
Correct answer: .40
The table says many lose consciousness at .30, most lose consciousness and some die at .40, and at .50 breathing stops and many die.
Source: South Dakota Commercial Driver License Manual — Section 2.22.1, Alcohol and Driving
11. What does the manual say about taking a drug that hides fatigue?
Correct answer: Don't use it, because rest is the only cure for fatigue
The Other Drugs section tells drivers not to use any drug that masks tiredness. Fatigue has one cure, and that is rest.
Source: South Dakota Commercial Driver License Manual — Section 2.22.2, Other Drugs
12. A chemical analysis shows a South Dakota driver was operating a CMV with an alcohol concentration of 0.05%. What does the manual say follows?
Correct answer: A commercial license disqualification of not less than one year
For a commercial vehicle the threshold is 0.04%, not 0.08%. A chemical analysis showing an alcohol concentration at or above 0.04% in the blood breaks SDCL 32-12A-44 and disqualifies the commercial license for at least a year.
Source: South Dakota Commercial Driver License Manual — General Information, Refusal of the Chemical Test
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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