Commercial Driving Cheat Sheet 2026

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

1. What does a Class 8 hazardous materials placard indicate? → The cargo is corrosive
2. When should you use the hand valve (trolley valve) on a combination vehicle? → Only to test trailer brakes; it should not be used to slow the vehicle while moving
3. What information must appear on a hazardous materials label? → The hazard class, division number if applicable, and packing group
4. When transporting hazardous materials, at what minimum distance must you park from a tunnel or bridge? → 300 feet
5. What is the purpose of a load board or load bar in an enclosed trailer? → To prevent cargo from shifting by creating a barrier across the trailer interior
6. What is the maximum number of hours a commercial driver can drive after 10 consecutive hours off duty? → 11 hours
7. If you discover a hazardous materials leak while en route, what is the correct first action? → Pull off the road safely, keep people away, and report immediately
8. Which emergency exit on a bus must always be kept clear of obstructions? → All emergency exits, including rear door and roof hatches
9. Which documents must a CDL passenger endorsement holder carry while on duty? → A valid CDL with the P endorsement and any required medical certificate
10. What is rearward amplification in a doubles or triples combination? → The tendency of the rear trailer to whip more violently than the front during swerving
11. What is a CSA score? → A safety measurement system used by FMCSA to identify high-risk carriers and drivers
12. What is FMCSA's role in commercial driving? → Regulating and providing safety oversight of commercial motor vehicles and their drivers
13. What is the recommended following distance for a commercial vehicle at highway speeds? → 6-7 seconds or more
14. At what blood alcohol concentration (BAC) is a CDL holder considered legally impaired while operating a commercial passenger vehicle? → 0.04%
15. What is the purpose of blocking and bracing cargo? → To prevent forward, backward, and lateral movement of cargo during transport
16. What is the maximum fine a driver can face for exceeding Hours of Service limits? → Up to $16,000 per violation
17. What is the penalty for using a hand-held cell phone while driving a commercial vehicle? → Fines up to $2,750 for the driver and disqualification for multiple offenses
18. What type of tie-down is most appropriate for securing heavy machinery on a flatbed? → Chains with binders rated for the weight of the load
19. What must a driver do with hazardous materials shipping papers when parked and out of the vehicle? → Leave them in a visible location in the cab, such as the driver's door pouch
20. How should a bus driver handle a passenger who wishes to board with a bicycle? → Follow the operator's specific policy on bicycle carriage
21. What is the 'packing group' designation used for in hazardous materials transport? → To indicate the degree of danger a hazardous material presents within its class
22. What blood alcohol concentration (BAC) is the legal limit for commercial drivers? → 0.04%
23. Which hazard class covers explosives? → Class 1
24. At what PSI should the low air pressure warning activate? → 60 PSI
25. What is the Emergency Response Guidebook (ERG) used for? → Identifying hazardous materials and providing emergency response guidance
26. What is the purpose of drain valves on air brake tanks? → To remove accumulated water and oil from the air tanks that could cause brake failure
27. What are the three classes of CDL? → Class A, B, and C
28. What hazard does a high center of gravity create for a commercial vehicle? → Increased rollover risk, especially during turns, lane changes, and on curves
29. Why is it dangerous to coast downhill in neutral or with the clutch depressed? → You lose the ability to use engine braking to control speed, requiring more brake use
30. What is the danger of an overloaded commercial vehicle? → It can cause brake failure, tire blowouts, steering difficulty, and structural damage