South Dakota CDL Practice Test Questions and Answers (SD) 7

5 out of 5 (35 votes)
80% Passing score
50 Questions
10 Mistakes allowed
Welcome to the South Dakota CDL General Knowledge Practice Test Number Seven. As you approach the vital step of obtaining your Commercial Driver's License (CDL) in 2026, this permit practice test stands as a pivotal tool in your preparation. Featuring 50 meticulously crafted South Dakota CDL test questions, this test demands a minimum of 40 correct answers for passing, reflecting the real-world rigor of the CDL permit test. It's important to note that each iteration of this DMV practice test presents the same set of SD permit test questions and answers. This consistency allows you to gauge your progress effectively and revisit any areas of difficulty until you achieve mastery. The DMV test questions encompass a wide range of topics, including road signs, rules of the road, traffic signals, and pavement markings, all tailored to the specific requirements of South Dakota's driving regulations. Our South Dakota DMV CDL practice test complements traditional drivers ed programs and Entry Level Driver Training courses, aligning with mandatory requirements set by state regulations. While it is not a substitute for certified driver's education courses, it significantly enhances your learning experience. By engaging with these DMV practice tests, you can reinforce and expand upon the knowledge acquired in your driver's education course, ensuring no stone is left unturned in your preparation. What sets this South Dakota DMV practice test apart is the immediate feedback and detailed explanations provided for each sample CDL test question. This feature not only clarifies the correct answers but also deepens your understanding of the underlying principles, making your learning process more comprehensive and effective. Behind the scenes, this SD CDL practice test is the product of professional driving instructors' expertise. These professionals, with their decades of teaching experience and a track record of helping thousands obtain their licenses, have meticulously written and reviewed each sample DMV test question. Their insights ensure that the permit practice test is not only challenging and relevant but also a true reflection of what to expect in the actual CDL permit test in 2026. So, delve into this practice test and harness its potential to guide you confidently towards achieving your CDL in South Dakota in 2026!
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Sample South Dakota CDL Test Questions - General Knowledge

Question 1

You should bleed air from hot tires to return their pressure to the normal reading.

  1. A TRUE
  2. B FALSE

Correct answer: B – FALSE

South Dakota's CDL guidance says not to release air from hot tires. Tire pressure increases with temperature, and bleeding air while the tires are hot can leave them underinflated after they cool. If a tire is too hot to touch, remain stopped until it has cooled.

Source: South Dakota Commercial Driver License Manual — § 2.14.2, “Driving in Very Hot Weather”.

Question 2

Some common cold medicines can cause driver drowsiness.

  1. A TRUE
  2. B FALSE

Correct answer: A – TRUE

Some prescription and over-the-counter drugs, including cold medicines, may cause drowsiness or otherwise reduce a person's ability to drive safely. Drivers should read warning labels and follow a doctor's instructions concerning possible effects. A medicine that interferes with safe driving should not be combined with driving duties.

Source: South Dakota Commercial Driver License Manual — § 2.22.2, “Other Drugs”.

Question 3

How far ahead should a commercial driver generally scan while driving?

  1. A 2 to 5 seconds
  2. B 5 to 10 seconds
  3. C 12 to 15 seconds
  4. D 15 to 25 seconds

Correct answer: C – 12 to 15 seconds

Good drivers generally look at least 12 to 15 seconds ahead—the distance the vehicle will travel during that time. At lower speeds, this is about one block; at highway speeds, it is approximately one-quarter mile. Drivers must still shift their attention between near and distant conditions.

Source: South Dakota Commercial Driver License Manual — § 2.4.1, “Seeing Ahead”.

Question 4

When should a driver turn off a vehicle's retarder?

  1. A Whenever the road is wet, icy, or covered with snow
  2. B Whenever the driver has slept less than six hours
  3. C Whenever the vehicle carries hazardous liquids
  4. D All of these answers are correct

Correct answer: A – Whenever the road is wet, icy, or covered with snow

The South Dakota CDL manual warns that a retarder may cause the drive wheels to skid when traction is poor. Drivers should turn it off whenever the road is wet, icy, or snow-covered. Retarder use is not determined by the driver's sleep time or simply by whether hazardous liquids are being carried.

Source: South Dakota Commercial Driver License Manual — § 2.3.4, “Retarders”.

Question 5

Before making a turn, how long must you keep the turn signal operating?

  1. A For at least the final 100 feet before the turn
  2. B Only while entering the turn
  3. C Only after the turn begins
  4. D Only when another vehicle is nearby

Correct answer: A – For at least the final 100 feet before the turn

South Dakota law requires a turn signal to operate continuously for at least the last 100 feet traveled before a turn. The CDL manual also instructs drivers to signal early and continue signaling through the maneuver. Advance signaling gives other road users notice of the vehicle’s intended movement.

Source: South Dakota Commercial Driver License Manual — § 2.5.1, “Signal Your Intentions”, SDCL § 32-26-18.1 – Turning from wrong lane prohibited--Turn signal required--Violation as misdemeanor

Question 6

Why should you avoid using the trailer hand valve during normal driving?

  1. A It can cause the trailer to skid
  2. B It applies the tractor brakes too strongly
  3. C It prevents the service brakes from releasing
  4. D It increases steering effort

Correct answer: A – It can cause the trailer to skid

The trailer hand valve should be used only when testing the trailer brakes. Using it while driving can lock or skid the trailer wheels and contribute to a jackknife. The foot brake applies the brakes throughout the combination and presents much less danger of causing this type of skid.

Source: South Dakota Commercial Driver License Manual — § 6.2.1, “Trailer Hand Valve”

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