Iowa CDL Test

1. Which statement best describes alcohol's effect on commercial driving?

2. If a critical warning light or gauge shows a serious malfunction while driving, what is the safest response?

3. Before a trip, mirrors should be adjusted so the driver can:

4. Before moving a commercial motor vehicle from a parked position, the driver should first:

5. When descending a long, steep grade, a driver should generally select a gear that:

6. What is the safest general rule when backing a commercial vehicle?

7. A good visual search for a CMV driver should include:

8. A turn signal should be used early enough to:

9. If a vehicle's speed increases while all other conditions remain the same, stopping distance generally:

10. Why should a heavily loaded CMV usually leave more following distance than a passenger car?

11. When meeting an oncoming vehicle at night, a driver should:

12. During heavy rain, a driver should reduce speed because:

13. A ball rolling into the street near a parked vehicle should make a driver anticipate that:

14. After a front tire blows out, which response sequence best protects control?

15. When the drive wheels lose traction and begin to spin, the driver should generally:

16. Who is responsible for checking that cargo is properly loaded and secured before and during the trip?

17. When inspecting tires during a pre-trip inspection, a driver should look for:

18. A driver who wants to transport certain hazardous materials requiring placards generally needs:

19. Before beginning a long downgrade, the driver should:

20. If a driver becomes too sleepy to drive safely, the driver should:

21. A driver discovers a safety defect during an en-route inspection. What should the driver do?

22. Before releasing the fifth wheel to uncouple a tractor from a semitrailer, the driver must ensure that:

23. A fire extinguisher carried on a CMV should be:

24. Off-tracking means that:

25. Why is coasting downhill in neutral unsafe?

26. When using a spotter while backing, the driver should:

27. Looking well ahead is especially important in a CMV because it:

28. The horn should be used primarily to:

29. A safe speed for a CMV should be based on:

30. An escape route is best described as:

31. At night, a driver should reduce speed when visibility is limited because:

32. A high-profile vehicle in strong crosswinds may require the driver to:

33. A line of stopped vehicles or another hazard hidden beyond a hill crest is a warning that:

34. If the service brakes fail while descending a long grade, which action should be part of the emergency response?

35. A locked-wheel skid is most likely when the driver:

36. Improper cargo weight distribution can:

37. Which fifth-wheel finding should cause the driver to refuse to move the combination until it is corrected?

38. Placards are used primarily to:

39. Brake fade on a long downgrade is caused by:

40. A driver is most likely to reduce fatigue risk by:

41. Moisture and oil in an air-brake system can:

42. If the low-air-pressure warning activates, the driver should:

43. Spring brakes are designed to:

44. A driver should monitor air-pressure gauges because they show:

45. If an air-brake leakage test shows pressure dropping faster than the current manual allows, the driver should:

46. A trailer skid is especially likely when the driver:

47. Before moving a tractor-semitrailer, the driver should verify that:

48. A combination vehicle's rollover risk increases when the driver:

49. Under federal CDL rules, a driver should expect the state to:

50. A driver should treat a damaged or leaking exhaust system as:

1. A driver should refuse to move a CMV when:

2. An unusually high engine-temperature reading should prompt the driver to:

3. The primary reason a CMV driver should wear a seat belt is to:

4. Before making a right turn in a large vehicle, the driver should:

5. A driver should select gears so the engine:

6. Blind-side backing is risky because:

7. A good mirror-checking routine is:

8. Before changing lanes, a driver should:

9. The safest time to reduce speed for a sharp curve is:

10. When passing a cyclist or roadside worker, a CMV driver should:

11. High beams should be dimmed when they could:

12. On snow or ice, a driver should:

13. A vehicle stopped with its door open near a travel lane should make the driver:

14. If the engine stalls while the vehicle is moving, the driver should:

15. During a drive-wheel skid, the driver should avoid:

16. After driving a short distance, the driver should recheck cargo securement because:

17. A pre-trip inspection of steering and suspension should look for:

18. When transporting regulated hazardous materials, the driver should know how to use:

19. On a downgrade, a safe speed should be selected so that:

20. Which condition can impair a driver's ability to operate a CMV safely?

21. A driver should record and report defects because the record:

22. A dashboard gauge should be interpreted by:

23. If a fire starts in a CMV, the driver should:

24. A high center of gravity makes a CMV more likely to:

25. Why should a driver select a lower gear before beginning a long downgrade?

26. When backing, the driver should stop and check the area if:

27. At an intersection, a CMV driver should search for:

28. To communicate a planned slowdown, a driver should:

29. Which statement best reflects how vehicle loading can affect stopping and handling?

30. A space cushion is valuable because it:

31. A driver is overdriving the headlights when the vehicle's stopping distance:

32. In hot weather, a driver should pay particular attention to:

33. When approaching a work zone, the driver should:

34. If a CMV becomes disabled on a roadway, the driver should:

35. The best way to prevent most skids is to:

36. A partially filled tank can be especially challenging because liquid cargo can:

37. A pre-trip check of lights and reflectors should confirm that they are:

38. If a hazardous-materials package is leaking, the driver should first:

39. An emergency escape ramp is intended for a vehicle that:

40. A break is most useful for fatigue when it includes:

41. Air-brake lag means that:

42. If a vehicle without antilock brakes locks wheels during an emergency stop, the driver should generally:

43. The tractor protection system helps:

44. Which condition can cause a tractor-trailer jackknife?

45. The trailer hand valve should not be used for:

46. Before turning with a trailer, the driver should consider trailer swing because:

47. FMCSA states that applicants must correctly answer at least what percentage of questions on the general and endorsement knowledge tests?

48. Why should a CDL applicant study the manual issued by the applicant's state?

49. Before driving, the driver should ensure the windshield and mirrors are:

50. Before coupling a tractor to a semitrailer, the driver should confirm that the trailer is: