SD CDL Cheat Sheet 2026

The 30 highest-yield SD CDL facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. When coupling a tractor to a semitrailer, what is the correct height for the trailer? → The trailer will be raised slightly when the tractor is backed under it.
2. Under normal driving conditions, what holds the spring brakes in the released position? → Air pressure
3. You are driving a truck with a sealed container load and cannot inspect the cargo inside. What are you still responsible for? → Making sure the gross weight and axle weight limits are not exceeded.
4. What is the primary reason that 'smooth bore' or unbaffled tank trucks are used for certain loads, like milk? → Sanitation regulations require tanks that can be thoroughly cleaned.
5. A driver is preparing for their pre-trip inspection. If the vehicle is equipped with an alcohol evaporator, what is its primary function? → To reduce the risk of ice forming in air brake valves during cold weather
6. Which part of the vehicle must you test during the brake system check? → Air, service, and parking brakes
7. Which document should always be in the vehicle during operation? → Registration, insurance, and inspection report
8. When inspecting the steering system, what is the maximum amount of acceptable play or 'slack' in a 20-inch steering wheel? → 2 inches
9. A driver feels too drowsy to continue driving safely. What is the BEST course of action? → Stop driving and rest until alert
10. You are driving a tank vehicle with baffled compartments. When making a turn, what type of liquid surge should you still be most concerned about? → Side-to-side surge
11. According to federal regulations, which of the following is a prohibited practice when transporting passengers? → Refueling the bus in a closed building with passengers on board.
12. Sample question 7 for Transporting Cargo & Passengers Safely? → Answer B
13. Sample question 9 for CDL Laws, Endorsements & Regulations? → Answer B
14. After how many hours of driving must a property-carrying CMV driver take a 30-minute rest break? → 8 hours
15. What should be done if a defect is found during inspection? → Report and repair it before driving
16. When backing a large commercial vehicle, what is the most important safety practice to follow? → Getting out of the vehicle to look at your path of travel before backing.
17. When backing a commercial vehicle, what is the best practice? → Use a helper and check mirrors
18. What is the maximum on-duty window (including driving time) allowed for a property-carrying CMV driver in a single shift? → 14 hours
19. Which of the following is the most critical rule regarding carry-on baggage on a bus? → Baggage must be stowed in a way that does not block any aisles or emergency exits.
20. Sample question 2 for CDL Laws, Endorsements & Regulations? → Answer B
21. A truck's 'headache rack' or front-end header board serves what primary purpose? → To protect the driver from shifting cargo during a sudden stop or crash.
22. Why is it important to perform a pre-trip inspection? → To ensure vehicle safety and legal compliance
23. What should you check for during a tire inspection? → Tread depth, inflation, and damage
24. Sample question 9 for Safe Driving Practices & Hazard Awareness? → Answer B
25. During the in-cab portion of the pre-trip inspection, what is the minimum required tread depth for the front steering axle tires? → 4/32 inch
26. Sample question 6 for Transporting Cargo & Passengers Safely? → Answer B
27. When must a driver re-check their cargo and securing devices after the initial inspection? → After driving for 3 hours or 150 miles, and after every break.
28. Sample question 1 for Transporting Cargo & Passengers Safely? → Answer B
29. Which of the following is a common sign of driver fatigue? → Difficulty maintaining lane position
30. When using the sleeper berth split provision, one of the two off-duty periods must be at least how long in the sleeper berth? → 8 hours