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Ohio CDL: Vehicle control and safe driving

Selected knowledge practice, not a complete licensing course or practical training.

Ohio CDL: Vehicle control and safe driving

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Question 1 of 64
  1. 1. An interstate truck's front tire has 3/32 inch of tread in a major groove. Does it meet the federal minimum for that position?
  2. 2. For a truck subject to federal tire rules, what minimum major-groove tread depth applies to a tire that is not on a front wheel?
  3. 3. A bus subject to federal equipment rules has a retreaded front tire with deep, undamaged tread. Is the tread depth enough to make that installation acceptable?
  4. 4. On a commercial vehicle subject to federal tire rules, a sidewall cut exposes the tire's reinforcing material. What should the driver do?
  5. 5. During a walk-around, you notice new rust streaks extending from wheel nuts. What do they suggest?
  6. 6. Two tires in a dual assembly are touching each other. How should you treat this finding?
  7. 7. You find grease on a truck's brake lining during inspection. What is the appropriate response?
  8. 8. Why is a cracked spring hanger more serious than a comfort problem?
  9. 9. A driver notices an exhaust leak beneath the sleeper area. Why must it be addressed?
  10. 10. Before climbing into a parked truck, which observation deserves investigation?
  11. 11. A driver checks the same vehicle daily. What approach best reduces overlooked inspection items?
  12. 12. A loose tool bag is resting where it could slide under the pedals. When should you secure it?
  13. 13. During the handbook's stationary hydraulic-brake check, the pedal keeps moving down while firm pressure is held. What does that indicate?
  14. 14. A parking brake fails to hold during its controlled inspection test. What should happen next?
  15. 15. In a safe low-speed brake check, the truck pulls noticeably to one side. What is the best conclusion?
  16. 16. After a normal pre-trip inspection, the coolant gauge starts rising unusually during the trip. What should the driver do?
  17. 17. A truck's drive wheels begin spinning as the driver accelerates on a wet surface. What is the appropriate immediate adjustment?
  18. 18. Why should a driver pulling a trailer avoid a jerky start?
  19. 19. A manually shifted truck is stopped uphill. When should the driver release a parking brake being used to prevent rollback?
  20. 20. On an uneven road, what steering-wheel grip gives a truck driver better control if a pothole jars the wheel?
  21. 21. Two suitable parking spaces are available. Which arrangement reduces a large vehicle's reversing risk?
  22. 22. Before backing a truck into an unfamiliar yard, what should the driver inspect outside the cab?
  23. 23. Why does the handbook recommend the lowest reverse gear and very slow backing?
  24. 24. When either approach is safely available, why favor a backing turn toward the driver's side?
  25. 25. Before a helper guides a truck's reversing maneuver, what should both people agree on?
  26. 26. Which truck transmission commonly requires double-clutching to change gears?
  27. 27. A driver changes to a truck with a different engine and gearbox. How should the driver establish suitable shift points?
  28. 28. A truck is approaching a long descent. When should the driver slow and select an appropriate lower gear?
  29. 29. Before a planned curve in a manually shifted truck, what preparation best supports control?
  30. 30. A truck has a retarder acting through the drive wheels. What does the handbook advise when those wheels have poor grip on ice?
  31. 31. Which scanning pattern matches the handbook's guidance for a commercial driver?
  32. 32. Before a tractor-trailer trip, in what alignment should the driver check the mirror adjustment?
  33. 33. A car appears small and distant in a truck's convex mirror. What must the driver allow for?
  34. 34. What is the safer way to use mirrors while a truck is moving on the highway?
  35. 35. A truck driver checked the adjacent lane, then turned on the signal. Why check again before and during the lane change?
  36. 36. While turning a long vehicle through a tight opening, what should mirror checks help the driver confirm?
  37. 37. A driver sees an open-load tarp suddenly ballooning in the mirrors. What is the best response?
  38. 38. After completing a turn, what should a truck driver do if the turn signal does not cancel itself?
  39. 39. A driver behind your truck seems hesitant to overtake. Should you wave them past as a promise that the road is clear?
  40. 40. At dusk in rain, which lighting choice helps other road users notice a commercial vehicle?
  41. 41. An interstate commercial truck breaks down on a highway shoulder. This is not a necessary traffic stop. Under the federal rule, what must the driver activate immediately?
  42. 42. A covered commercial truck is disabled on a rural highway shoulder where warning devices are required. When should the driver place them?
  43. 43. On a straight rural divided highway, an interstate truck is disabled on the shoulder with clear sight lines. Which triangle arrangement matches the federal rule?
  44. 44. A covered truck is disabled on the shoulder of a straight, rural two-way road with no sight obstruction. Where do the two farther triangles go under the general federal arrangement?
  45. 45. A disabled commercial truck is within 500 feet of a curve that hides it from approaching traffic. How does the federal rule address the warning in that direction?
  46. 46. An interstate truck is stopped with fuel leaking near the shoulder. What warning-device choice avoids adding an ignition source near the leak?
  47. 47. A driver estimates stopping space using only the distance traveled after braking starts. What has been left out of the handbook's basic total?
  48. 48. With other conditions comparable, the handbook says doubling speed has roughly what effect on braking distance, excluding perception and reaction?
  49. 49. After unloading a truck, may the driver assume it can now follow closer because it must stop sooner?
  50. 50. Rain has made the pavement slippery but traffic is still moving quickly. What should a truck driver change?
  51. 51. It is below freezing and a shaded stretch of road looks wet rather than snowy. What should the driver consider?
  52. 52. A manually shifted truck begins hydroplaning through standing water. Which response follows the handbook's guidance?
  53. 53. A loaded truck has a high center of gravity. Does the speed posted for a curve guarantee that it will not roll over at that speed?
  54. 54. At night, oncoming traffic requires low beams. What should a truck driver do if the visible road becomes shorter than the truck's stopping distance?
  55. 55. Using the handbook's basic following-gap guideline in good conditions, what gap should a 40-foot truck leave at 35 mph?
  56. 56. Using the handbook's basic guideline in good conditions, what following gap should a 60-foot rig leave at 50 mph?
  57. 57. How can a driver measure the following gap without estimating a distance in feet?
  58. 58. A car is following a truck too closely. Which adjustment helps reduce the need for a sudden stop?
  59. 59. An empty, high-sided truck emerges from a sheltered tunnel into strong crosswinds. What deserves extra attention?
  60. 60. A cargo van cleared a low structure while loaded. After unloading, is that previous clearance enough proof that it will fit again?
  61. 61. A low-clearance trailer approaches a sharply raised rail crossing. What should the driver establish before attempting to cross?
  62. 62. Why should a large-truck driver avoid swinging left at the start of a planned right turn?
  63. 63. A driver turns a long truck left too early at an intersection. What can the rear portion do?
  64. 64. A gap was adequate when the driver crossed a road in a car. Is it automatically adequate for a heavily loaded truck making the same crossing?
Review all 64 questions with answers

  1. An interstate truck's front tire has 3/32 inch of tread in a major groove. Does it meet the federal minimum for that position?

    Correct answer: No. A front tire needs at least 4/32 inch.

    For a truck, truck tractor or bus subject to this rule, front-wheel tires need at least 4/32 inch in a major tread groove, measured away from tie bars, humps and fillets. A 3/32-inch reading is below that minimum.

    Source: 49 CFR 393.75(b); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  2. For a truck subject to federal tire rules, what minimum major-groove tread depth applies to a tire that is not on a front wheel?

    Correct answer: 2/32 inch.

    The federal minimum is 2/32 inch for these other tires. The separate front-wheel requirement is 4/32 inch. Measure in a major groove, away from raised tie bars, humps and fillets.

    Source: 49 CFR 393.75(c); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  3. A bus subject to federal equipment rules has a retreaded front tire with deep, undamaged tread. Is the tread depth enough to make that installation acceptable?

    Correct answer: No. Retreaded tires are prohibited on the front wheels of the bus.

    Federal rules prohibit regrooved, recapped and retreaded tires on the front wheels of a bus. Adequate tread depth does not remove that position-specific restriction; this is not a ban on every rear tire.

    Source: 49 CFR 393.75(d); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  4. On a commercial vehicle subject to federal tire rules, a sidewall cut exposes the tire's reinforcing material. What should the driver do?

    Correct answer: Have the unsafe tire corrected before operating the vehicle.

    Exposed body-ply or belt material is a prohibited tire condition, whether exposed through the tread or sidewall. Tread depth and the presence of a neighboring tire do not make that tire safe.

    Source: 49 CFR 393.75(a)(1), (a)(4); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  5. During a walk-around, you notice new rust streaks extending from wheel nuts. What do they suggest?

    Correct answer: The nuts may be loose and their tightness needs checking.

    Rust trails can indicate movement at a wheel nut. Check the assembly rather than dismissing the streaks as cosmetic. The handbook also calls for a tightness recheck after a wheel has recently been changed.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.3 Wheel and Rim Problems; physical PDF page 19 (printed 2-1); reviewed September 14, 2026. ↗

  6. Two tires in a dual assembly are touching each other. How should you treat this finding?

    Correct answer: As a tire defect to resolve before the vehicle is driven.

    Dual tires should not rub against each other or vehicle components. Matching size and apparently good tread do not cancel the need to investigate contact and correct the unsafe condition.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.3 Tire Problems; physical PDF page 19 (printed 2-1); reviewed September 14, 2026. ↗

  7. You find grease on a truck's brake lining during inspection. What is the appropriate response?

    Correct answer: Have the brake defect corrected before starting the trip.

    Oil, grease or brake fluid on friction material is a brake defect. A sound drum does not make contaminated lining acceptable, and the parking brake is not a substitute for a safe service-brake system.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.3 Bad Brake Drums or Shoes; physical PDF page 20 (printed 2-2); reviewed September 14, 2026. ↗

  8. Why is a cracked spring hanger more serious than a comfort problem?

    Correct answer: It can allow the axle to move out of its proper position.

    The suspension supports the vehicle and load while keeping axles correctly positioned. Damaged hangers or related mounting parts can threaten control and require attention, even before several spring leaves have failed.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.3 Suspension System Defects; physical PDF page 20 (printed 2-2); reviewed September 14, 2026. ↗

  9. A driver notices an exhaust leak beneath the sleeper area. Why must it be addressed?

    Correct answer: Poisonous exhaust can enter the cab or sleeper.

    A damaged exhaust system can let poisonous fumes into occupied spaces. Check leaking or unsecured exhaust components and have the defect corrected; opening a window is not a repair.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.3 Exhaust System Defects; physical PDF page 21 (printed 2-3); reviewed September 14, 2026. ↗

  10. Before climbing into a parked truck, which observation deserves investigation?

    Correct answer: A fresh fluid puddle under the engine area.

    The approach inspection looks for clues such as fresh leaks, damage or an unusual lean, as well as people and obstacles around the vehicle. Investigate a fresh puddle instead of discovering the problem after departure.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.5 Approaching the Vehicle; physical PDF page 21 (printed 2-3); reviewed September 14, 2026. ↗

  11. A driver checks the same vehicle daily. What approach best reduces overlooked inspection items?

    Correct answer: Use a consistent inspection routine on each trip.

    A repeatable method helps prevent omissions. Familiarity with a vehicle or a trouble-free previous trip does not show that its current condition is safe.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.5 Method of Inspection; physical PDF page 21 (printed 2-3); reviewed September 14, 2026. ↗

  12. A loose tool bag is resting where it could slide under the pedals. When should you secure it?

    Correct answer: Before moving, so it cannot obstruct the controls.

    Loose cab objects can interfere with driving controls or strike occupants in a crash. Secure them before driving rather than relying on their current position.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.5 Get In Vehicle; physical PDF page 24 (printed 2-6); reviewed September 14, 2026. ↗

  13. During the handbook's stationary hydraulic-brake check, the pedal keeps moving down while firm pressure is held. What does that indicate?

    Correct answer: A possible leak or other fault that needs repair before driving.

    A pedal that does not hold its position during this check can indicate a hydraulic leak or another brake problem. Get it corrected before driving. Air-brake vehicles require their own different checks.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.5 Test for Hydraulic Leaks; physical PDF page 24 (printed 2-6); reviewed September 14, 2026. ↗

  14. A parking brake fails to hold during its controlled inspection test. What should happen next?

    Correct answer: Have the faulty parking brake repaired before operation.

    The parking brake must hold the vehicle as intended. A failed test is a defect to fix, not a reason to substitute an improvised parking routine.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.5 Test Parking Brakes; physical PDF page 25 (printed 2-7); reviewed September 14, 2026. ↗

  15. In a safe low-speed brake check, the truck pulls noticeably to one side. What is the best conclusion?

    Correct answer: A brake or related safety problem needs investigation.

    Pulling, unusual pedal feel or delayed stopping action can signal trouble. Resolve an unsafe condition before the trip instead of treating steering compensation as a repair.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.5 Test Service Brake Stopping Action; physical PDF page 25 (printed 2-7); reviewed September 14, 2026. ↗

  16. After a normal pre-trip inspection, the coolant gauge starts rising unusually during the trip. What should the driver do?

    Correct answer: Respond to the warning and investigate at a safe stopping place.

    Pre-trip inspection is not the end of monitoring. Watch instruments and use sight, sound, smell and feel for developing problems; do not let a reassuring earlier check override a new warning.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.1.6 Inspection during a Trip; physical PDF page 25 (printed 2-7); reviewed September 14, 2026. ↗

  17. A truck's drive wheels begin spinning as the driver accelerates on a wet surface. What is the appropriate immediate adjustment?

    Correct answer: Ease off the accelerator to reduce the spinning.

    Too much driving power for the available traction can make the wheels spin and threaten control. Reduce acceleration and build speed gradually when grip is poor.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.2.1 Accelerating; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  18. Why should a driver pulling a trailer avoid a jerky start?

    Correct answer: It can place damaging loads on the coupling and drivetrain.

    A smooth, gradual start protects the coupling and other mechanical components and helps maintain control. A harsh surge is not a useful way to test a connection.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.2.1 Accelerating; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  19. A manually shifted truck is stopped uphill. When should the driver release a parking brake being used to prevent rollback?

    Correct answer: When enough engine power is applied to prevent rolling backward.

    Coordinate the clutch, power and brakes so the vehicle does not roll backward into someone behind it. When using the parking brake for this purpose, release it after sufficient power is available.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.2.1 Accelerating; physical PDF page 25 (printed 2-7); reviewed September 14, 2026. ↗

  20. On an uneven road, what steering-wheel grip gives a truck driver better control if a pothole jars the wheel?

    Correct answer: A firm grip with hands on opposite sides of the wheel.

    Holding the wheel firmly with both hands on opposite sides helps resist an unexpected pull from a pothole or curb. This is a control habit, not a guarantee against loss of control.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.2.2 Steering; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  21. Two suitable parking spaces are available. Which arrangement reduces a large vehicle's reversing risk?

    Correct answer: The one that allows a forward departure when leaving.

    Avoid reversing when a safe forward departure is practical. Backing exposes areas the driver cannot fully see, so parking position can remove an unnecessary maneuver.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.2.4 Backing Safely; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  22. Before backing a truck into an unfamiliar yard, what should the driver inspect outside the cab?

    Correct answer: The full path, including side space and overhead obstructions.

    Walk and inspect the intended path before backing. Check the sides, overhead space and surrounding hazards, not just the patch of ground immediately behind the wheels.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.2.4 Look at Your Path; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  23. Why does the handbook recommend the lowest reverse gear and very slow backing?

    Correct answer: They leave more time to correct steering and stop.

    Low reversing speed helps the driver correct small steering errors and stop promptly. It does not remove blind spots or replace an outside check.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.2.4 Back Slowly; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  24. When either approach is safely available, why favor a backing turn toward the driver's side?

    Correct answer: The driver can see the rear path better from that side.

    Driver-side backing improves visibility of the rear path, including through the side window. Continue checking both sides and stop to investigate uncertainty; improved visibility does not eliminate risk.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.2.4 Back and Turn Toward the Driver's Side; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  25. Before a helper guides a truck's reversing maneuver, what should both people agree on?

    Correct answer: Clear hand signals, especially the signal to stop.

    The driver and helper need a shared set of understandable signals, with a definite stop signal. Position the helper where the driver can see them and do not keep moving if communication or clearance becomes uncertain.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.2.4 Use a Helper; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  26. Which truck transmission commonly requires double-clutching to change gears?

    Correct answer: An unsynchronized manual transmission.

    Most heavy-vehicle unsynchronized manual transmissions use double-clutching. A synchronized manual does not require that technique merely because it is a manual. Learn the system fitted to the actual vehicle.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.3.1 Manual Transmissions; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  27. A driver changes to a truck with a different engine and gearbox. How should the driver establish suitable shift points?

    Correct answer: Learn that vehicle's operating ranges and use its gauges.

    Shift points depend on the vehicle. Use the manufacturer's operating information and the tachometer or known road-speed ranges; some systems use progressive shifting rather than one fixed RPM for every gear.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.3.1 Knowing When to Shift Up; physical PDF page 26 (printed 2-8); reviewed September 14, 2026. ↗

  28. A truck is approaching a long descent. When should the driver slow and select an appropriate lower gear?

    Correct answer: Before beginning the descent.

    Choose the safe speed and suitable gear before starting down. Appropriate engine braking helps control the descent and avoids depending on heavy service-brake use that can overheat the brakes.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.3.1 Before Starting Down a Hill; physical PDF page 27 (printed 2-9); reviewed September 14, 2026. ↗

  29. Before a planned curve in a manually shifted truck, what preparation best supports control?

    Correct answer: Reduce speed and select the appropriate gear before entering.

    Complete the planned speed reduction and gear selection before the curve. This leaves the driver better able to steer smoothly without an avoidable shift or abrupt braking demand during the turn.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.3.1 Before Entering a Curve; physical PDF page 27 (printed 2-9); reviewed September 14, 2026. ↗

  30. A truck has a retarder acting through the drive wheels. What does the handbook advise when those wheels have poor grip on ice?

    Correct answer: Turn the retarder off to avoid provoking a drive-wheel skid.

    A retarder can demand more grip than slippery drive tires have available. The handbook advises turning it off on wet, icy or snow-covered roads; understand the vehicle's instructions and use a suitably low speed.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.3.4 Retarders; physical PDF page 27 (printed 2-9); reviewed September 14, 2026. ↗

  31. Which scanning pattern matches the handbook's guidance for a commercial driver?

    Correct answer: Look at least 12 to 15 seconds ahead while also checking nearer hazards.

    The 12-to-15-second look-ahead guidance gives time to plan. It is not a following-gap rule or a reason to stare at one point: shift attention between near, far and surrounding traffic.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.4.1 Seeing Ahead; physical PDF page 28 (printed 2-10); reviewed September 14, 2026. ↗

  32. Before a tractor-trailer trip, in what alignment should the driver check the mirror adjustment?

    Correct answer: With the combination straight, showing a small vehicle reference.

    Check adjustment with the trailer straight. Showing part of the vehicle gives a reference for judging other images. Proper adjustment still leaves blind areas that need careful monitoring.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.4.2 Mirror Adjustment; physical PDF page 28 (printed 2-10); reviewed September 14, 2026. ↗

  33. A car appears small and distant in a truck's convex mirror. What must the driver allow for?

    Correct answer: It may be closer than its image makes it appear.

    A convex mirror gives a wider view but makes objects look smaller and farther away. Account for that distortion when judging nearby traffic rather than treating apparent distance as actual clearance.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.4.2 How to Use Mirrors; physical PDF page 28 (printed 2-10); reviewed September 14, 2026. ↗

  34. What is the safer way to use mirrors while a truck is moving on the highway?

    Correct answer: Make brief checks and return attention to the road ahead.

    Regular, quick mirror checks maintain awareness without leaving the forward road unwatched for too long. Travel continues while the driver's eyes are turned away.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.4.2 How to Use Mirrors; physical PDF page 28 (printed 2-10); reviewed September 14, 2026. ↗

  35. A truck driver checked the adjacent lane, then turned on the signal. Why check again before and during the lane change?

    Correct answer: Another vehicle may have entered a blind area since the first check.

    Conditions change between an initial check and a maneuver. The handbook calls for repeated checks before, after signaling, as the change begins and after completion; signaling does not create a guaranteed gap.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.4.2 Lane Changes; physical PDF page 28 (printed 2-10); reviewed September 14, 2026. ↗

  36. While turning a long vehicle through a tight opening, what should mirror checks help the driver confirm?

    Correct answer: The rear of the vehicle is clearing nearby objects.

    A clear front path does not establish clearance for the rear of a long vehicle. Monitor the rear's movement and nearby space throughout a tight turn.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.4.2 Turns; physical PDF page 28 (printed 2-10); reviewed September 14, 2026. ↗

  37. A driver sees an open-load tarp suddenly ballooning in the mirrors. What is the best response?

    Correct answer: Treat it as a possible securement problem and check safely.

    Mirrors can reveal developing cargo problems such as flapping covers or loose restraints. Investigate safely instead of waiting for a load to escape.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.4.2 Check Your Vehicle; physical PDF page 28 (printed 2-10); reviewed September 14, 2026. ↗

  38. After completing a turn, what should a truck driver do if the turn signal does not cancel itself?

    Correct answer: Cancel it so other road users are not misled.

    Signal early and through the maneuver, then cancel the signal when the turn is complete. A lingering signal can cause other drivers to predict a turn the truck will not make.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.5.1 Turns; physical PDF page 29 (printed 2-11); reviewed September 14, 2026. ↗

  39. A driver behind your truck seems hesitant to overtake. Should you wave them past as a promise that the road is clear?

    Correct answer: No. Let that driver judge and perform their own safe pass.

    Do not signal that it is safe for another driver to pass. Your view and their assessment may differ, and a wave can encourage a maneuver whose safety you cannot guarantee.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.5.1 Don't Direct Traffic; physical PDF page 29 (printed 2-11); reviewed September 14, 2026. ↗

  40. At dusk in rain, which lighting choice helps other road users notice a commercial vehicle?

    Correct answer: Use low-beam headlights, not just clearance or identification lights.

    Use headlights to make the vehicle visible when conditions reduce visibility. Clearance and identification lights are not a substitute; low beams avoid the additional glare of high beams.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.5.2 When It's Hard to See; physical PDF page 29 (printed 2-11); reviewed September 14, 2026. ↗

  41. An interstate commercial truck breaks down on a highway shoulder. This is not a necessary traffic stop. Under the federal rule, what must the driver activate immediately?

    Correct answer: The vehicle's hazard warning flashers.

    The rule calls for immediate hazard flashers for this stop. Flashers must be used while required warning devices are being placed and picked up; they do not replace those devices.

    Source: 49 CFR 392.22(a); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  42. A covered commercial truck is disabled on a rural highway shoulder where warning devices are required. When should the driver place them?

    Correct answer: As soon as possible, and no later than 10 minutes.

    Ten minutes is an outside deadline, not a suggested delay. Where the requirement applies, place the devices as soon as possible. Necessary traffic stops and the rule's special exceptions are different situations.

    Source: 49 CFR 392.22(b)(1); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  43. On a straight rural divided highway, an interstate truck is disabled on the shoulder with clear sight lines. Which triangle arrangement matches the federal rule?

    Correct answer: One within 10 feet at the traffic side of the rear; others 100 and 200 feet toward approaching traffic.

    For a divided or one-way highway, the two farther devices go 100 and 200 feet toward approaching traffic, centered in the occupied lane or shoulder. The nearest goes at the traffic side within 10 feet of the rear. An obstruction to sight can require adjusted placement.

    Source: 49 CFR 392.22(b)(2)(v); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  44. A covered truck is disabled on the shoulder of a straight, rural two-way road with no sight obstruction. Where do the two farther triangles go under the general federal arrangement?

    Correct answer: About 100 feet ahead and 100 feet behind, in the occupied shoulder.

    The general arrangement warns traffic from both directions: one device about 100 feet each way in the lane or shoulder occupied by the truck, plus a near device about 10 feet away on its traffic side toward approaching traffic.

    Source: 49 CFR 392.22(b)(1)(i)-(iii); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  45. A disabled commercial truck is within 500 feet of a curve that hides it from approaching traffic. How does the federal rule address the warning in that direction?

    Correct answer: Place it 100 to 500 feet from the truck where it gives ample advance warning.

    When a curve, hillcrest or other obstruction limits the view in this situation, move the warning in that direction to a suitable point 100 to 500 feet from the truck. The purpose is to warn approaching road users early, not hide the device with the vehicle.

    Source: 49 CFR 392.22(b)(2)(iv); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  46. An interstate truck is stopped with fuel leaking near the shoulder. What warning-device choice avoids adding an ignition source near the leak?

    Correct answer: Use reflective triangles rather than lighting a flare near the fuel.

    Do not introduce a flame where it could ignite leaking flammable liquid or gas. The federal rule prohibits a flame-producing warning at a distance that would not prevent a fire or explosion; reflective triangles avoid that ignition source.

    Source: 49 CFR 392.22(b)(2)(vi); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗

  47. A driver estimates stopping space using only the distance traveled after braking starts. What has been left out of the handbook's basic total?

    Correct answer: The distance traveled while perceiving the hazard and reacting.

    The basic total includes perception, reaction and braking distances. The vehicle travels before the driver applies the brakes as well as during braking. System-specific delays, such as air-brake lag, also matter in applicable vehicles.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.6.1 Stopping Distance; physical PDF page 31 (printed 2-13); reviewed September 14, 2026. ↗

  48. With other conditions comparable, the handbook says doubling speed has roughly what effect on braking distance, excluding perception and reaction?

    Correct answer: It makes the braking distance about four times as long.

    The handbook illustrates a roughly fourfold braking-distance increase when speed doubles. This comparison concerns braking distance, not a claim that every component of total stopping distance grows by the same factor.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.6.1 The Effect of Speed on Stopping Distance; physical PDF page 31 (printed 2-13); reviewed September 14, 2026. ↗

  49. After unloading a truck, may the driver assume it can now follow closer because it must stop sooner?

    Correct answer: No. Reduced tire traction can make an empty truck take longer to stop.

    Do not assume less load guarantees a shorter stop. The handbook warns that reduced traction can make an empty truck's stopping performance worse. Leave a gap suitable for the actual vehicle and conditions.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.6.1 The Effect of Vehicle Weight on Stopping Distance; physical PDF page 32 (printed 2-14); reviewed September 14, 2026. ↗

  50. Rain has made the pavement slippery but traffic is still moving quickly. What should a truck driver change?

    Correct answer: Reduce speed and allow more stopping space for the available traction.

    Wet pavement reduces traction and can lengthen stopping distance. Lower speed and additional space give more room to react and stop; a posted maximum is not a guarantee for the weather.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.6.2 Slippery Surfaces; physical PDF page 32 (printed 2-14); reviewed September 14, 2026. ↗

  51. It is below freezing and a shaded stretch of road looks wet rather than snowy. What should the driver consider?

    Correct answer: The apparent wetness may be a thin layer of clear ice.

    Clear ice can show the pavement beneath it and look like water. Below-freezing temperatures and shaded areas are reasons for extra caution, not reasons to rule out ice.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.6.2 Identifying Slippery Surfaces; physical PDF page 32 (printed 2-14); reviewed September 14, 2026. ↗

  52. A manually shifted truck begins hydroplaning through standing water. Which response follows the handbook's guidance?

    Correct answer: Release the accelerator and disengage the clutch; avoid braking while hydroplaning.

    Water can separate the tires from the road. The handbook advises easing off power and, in a manual vehicle, pushing in the clutch so the wheels turn freely, rather than braking while hydroplaning. Avoid abrupt inputs and reduce speed before standing water.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.6.2 Hydroplaning; physical PDF page 32 (printed 2-14); reviewed September 14, 2026. ↗

  53. A loaded truck has a high center of gravity. Does the speed posted for a curve guarantee that it will not roll over at that speed?

    Correct answer: No. Its safe cornering speed may need to be lower.

    A truck can roll over even while its tires retain grip. Load and center of gravity affect stability, so slow sufficiently before the curve rather than assuming the sign guarantees safety for the vehicle.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.6.3 Speed and Curves; physical PDF page 32 (printed 2-14); reviewed September 14, 2026. ↗

  54. At night, oncoming traffic requires low beams. What should a truck driver do if the visible road becomes shorter than the truck's stopping distance?

    Correct answer: Slow enough to stop within the road distance that can be seen.

    Speed must fit the available view as well as the road surface. If the truck cannot stop within the illuminated road ahead, reduce speed; another driver's lights are not a reliable substitute.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.6.4 Speed and Distance Ahead; physical PDF page 32 (printed 2-14); reviewed September 14, 2026. ↗

  55. Using the handbook's basic following-gap guideline in good conditions, what gap should a 40-foot truck leave at 35 mph?

    Correct answer: At least 4 seconds.

    The guideline is one second per 10 feet of vehicle length below 40 mph: 40 divided by 10 gives four seconds. This is a starting guideline, not a guarantee for poor weather or other hazards.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.1 Space Ahead; Figure 2.12; physical PDF page 33 (printed 2-15); reviewed September 14, 2026. ↗

  56. Using the handbook's basic guideline in good conditions, what following gap should a 60-foot rig leave at 50 mph?

    Correct answer: At least 7 seconds.

    Allow six seconds for 60 feet of length and add one second above 40 mph, for at least seven seconds. Increase the space further when traction, visibility or other conditions demand it.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.1 Space Ahead; Figure 2.12; physical PDF page 33 (printed 2-15); reviewed September 14, 2026. ↗

  57. How can a driver measure the following gap without estimating a distance in feet?

    Correct answer: Count the time from the lead vehicle passing a fixed landmark until the truck reaches it.

    Choose a fixed point ahead and time the interval between the lead vehicle and your vehicle reaching that same point. Compare it with a suitable following-time guideline and drop back if needed.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.1 Space Ahead; physical PDF page 33 (printed 2-15); reviewed September 14, 2026. ↗

  58. A car is following a truck too closely. Which adjustment helps reduce the need for a sudden stop?

    Correct answer: Open more space ahead and make speed changes gradually.

    More space ahead lets you slow and react gradually. Signal planned changes early and avoid retaliatory braking or acceleration, which increases risk without controlling the tailgater.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.2 Dealing with Tailgaters Safely; physical PDF page 34 (printed 2-16); reviewed September 14, 2026. ↗

  59. An empty, high-sided truck emerges from a sheltered tunnel into strong crosswinds. What deserves extra attention?

    Correct answer: Lateral movement and clearance from vehicles alongside.

    Strong winds can push a vehicle sideways, especially a light one, and exposure can change suddenly outside a tunnel. Maintain control and side space instead of traveling unnecessarily alongside other vehicles.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.3 Strong Winds; physical PDF page 34 (printed 2-16); reviewed September 14, 2026. ↗

  60. A cargo van cleared a low structure while loaded. After unloading, is that previous clearance enough proof that it will fit again?

    Correct answer: No. The unloaded vehicle may ride higher, so clearance must be checked.

    Suspension position can change vehicle height with loading. Do not assume a previous passage proves clearance now; know the current height, assess conditions and choose another route when clearance is uncertain.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.4 Space Overhead; physical PDF page 34 (printed 2-16); reviewed September 14, 2026. ↗

  61. A low-clearance trailer approaches a sharply raised rail crossing. What should the driver establish before attempting to cross?

    Correct answer: That the vehicle can clear the crest without getting hung up.

    A long, low trailer can become stranded on a raised crossing even when its front wheels pass. Ground clearance and the road profile must be suitable; do not gamble on momentum to get over the crest.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.5 Space Below; physical PDF page 35 (printed 2-17); reviewed September 14, 2026. ↗

  62. Why should a large-truck driver avoid swinging left at the start of a planned right turn?

    Correct answer: A following driver may mistake it for a left turn and enter the space on the right.

    An early swing left opens a tempting gap on the right and can mislead following traffic. Plan the turn slowly, monitor clearance and traffic, and do not treat the needed turning space as automatic right-of-way.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.6 Right Turns; Figure 2.13; physical PDF page 35 (printed 2-17); reviewed September 14, 2026. ↗

  63. A driver turns a long truck left too early at an intersection. What can the rear portion do?

    Correct answer: Cut inside the front path and strike a vehicle or object on the left.

    The rear wheels of a long vehicle follow an inside path in a turn. Starting the left turn too early can bring the vehicle's left side into nearby traffic or objects; allow space for the whole vehicle.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.6 Left Turns; physical PDF page 35 (printed 2-17); reviewed September 14, 2026. ↗

  64. A gap was adequate when the driver crossed a road in a car. Is it automatically adequate for a heavily loaded truck making the same crossing?

    Correct answer: No. Slower acceleration and greater length can require a much larger gap.

    A loaded truck may accelerate more slowly and needs more time for its entire length to clear the road. Before entering, make sure the whole vehicle can complete the crossing before conflicting traffic reaches it.

    Source: Ohio Commercial Driver License Manual, HSY 7605 7/26, Section 2 (July 2017); 2.7.7 Space Needed to Cross or Enter Traffic; physical PDF page 35 (printed 2-17); reviewed September 14, 2026. ↗

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Ohio CDL: Vehicle control and safe driving

64 questions on inspection, backing, gears, mirrors, speed, stopping and space.

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Use the right kind of distance

Looking 12–15 seconds ahead is a scanning habit, not the following-gap rule. The handbook's good-condition following guideline uses at least one second per 10 feet of vehicle length below 40 mph, with another second above 40 mph. Thus a 40-foot truck at 35 mph starts with four seconds, while a 60-foot rig at 50 mph starts with seven. Poor conditions require more space.

Stopping distance includes travel before the brake pedal is applied. In turns, rear wheels follow an inside path: a clear front bumper does not prove rear clearance. Know your vehicle's current height and load, and stop to check uncertain backing clearance.

Ohio following-space guidance · page 2-15Ohio turning diagrams · page 2-17

Independent knowledge practice. The cited paragraphs and their scope control each rule question; the handbook's diagrams are linked at their official source, not reproduced here.