CDL Test Questions and Answers

Good drivers look 12 to 15 seconds ahead. At highway speeds, this is about a quarter of a mile. This gives you time to adjust speed or change lanes to avoid hazards.

Study focusChoose safe speed, spacing, and visual search habits for commercial vehicles.

Common trapDriving at passenger-car speeds without accounting for weight, space, weather, or grade.

Federal regulations require a minimum tread depth of 4/32 inch in every major groove on front (steering) tires. Other tires require at least 2/32 inch.

Study focusUse pre-trip inspection habits to identify unsafe vehicle-system defects before driving.

Common trapMemorizing a walk-around order without understanding which defects make the vehicle unsafe.

Use high beams whenever you can to see further ahead, provided it is safe and legal. You must dim them when within 500 feet of an oncoming vehicle or when following another vehicle within 500 feet.

Study focusApply core CDL safe-driving rules to common road and vehicle situations.

Common trapMemorizing rules without applying them to driving scenarios.

Hydroplaning occurs when water builds up in front of your tires, causing them to lift off the road surface. You lose steering and braking control. To recover, release the accelerator and do not brake hard.

Study focusUse pre-trip inspection habits to identify unsafe vehicle-system defects before driving.

Common trapMemorizing a walk-around order without understanding which defects make the vehicle unsafe.

When a tire blows out, grip the steering wheel firmly and stay off the brakes. Braking hard can cause a skid or loss of control. Let the vehicle slow down naturally before applying brakes gently.

Study focusUse pre-trip inspection habits to identify unsafe vehicle-system defects before driving.

Common trapMemorizing a walk-around order without understanding which defects make the vehicle unsafe.

Safety is the most important reason for a pre-trip inspection. Finding and fixing a defect before driving helps prevent breakdowns and crashes on the road.

Study focusUse pre-trip inspection habits to identify unsafe vehicle-system defects before driving.

Common trapMemorizing a walk-around order without understanding which defects make the vehicle unsafe.

Electrical fires require a B:C or A:B:C rated extinguisher. Using water or water-based foam on an electrical fire can result in a severe electric shock.

Study focusApply safe loading, separation, parking, routing, and emergency-response decisions for hazmat.

Common trapChoosing a convenient action instead of the action that protects people and isolates the hazard.

The rule of thumb is 1 second of following distance for every 10 feet of vehicle length at speeds under 40 mph. For speeds over 40 mph, add 1 additional second. A 60-foot truck at 55 mph needs 7 seconds of space.

Study focusChoose safe speed, spacing, and visual search habits for commercial vehicles.

Common trapDriving at passenger-car speeds without accounting for weight, space, weather, or grade.

The first step in a vehicle fire is to get the vehicle off the road and stop in an open area, clear of buildings, trees, brush, and other vehicles to prevent the fire from spreading.

Study focusApply safe loading, separation, parking, routing, and emergency-response decisions for hazmat.

Common trapChoosing a convenient action instead of the action that protects people and isolates the hazard.

If you are being tailgated, increase the space in front of your vehicle. This allows you to brake more smoothly and gradually, reducing the chance that the tailgater will crash into your rear.

Study focusChoose safe speed, spacing, and visual search habits for commercial vehicles.

Common trapDriving at passenger-car speeds without accounting for weight, space, weather, or grade.

You should brake to a safe speed before entering a curve. Once in the curve, maintain speed or accelerate slightly, as this helps stabilize the vehicle. Never brake hard in a curve.

Study focusChoose safe speed, spacing, and visual search habits for commercial vehicles.

Common trapDriving at passenger-car speeds without accounting for weight, space, weather, or grade.

Most serious skids result from driving too fast for road conditions, over-braking, over-steering, or over-accelerating. Speed is the primary factor in losing traction.

Study focusUse pre-trip inspection habits to identify unsafe vehicle-system defects before driving.

Common trapMemorizing a walk-around order without understanding which defects make the vehicle unsafe.

At night, your visibility is limited to the reach of your headlights. You must adjust your speed so you can safely stop within that visible distance.

Study focusUse inspection habits to catch unsafe defects before driving.

Common trapChecking only obvious items and missing brake, tire, coupling, or defect-report steps.

While avoiding fines is good, safety is the primary reason for inspections. A defect found during an inspection can prevent a breakdown or fatal crash.

Study focusUse inspection habits to catch unsafe defects before driving.

Common trapChecking only obvious items and missing brake, tire, coupling, or defect-report steps.

You should check your mirrors regularly (about every 5 to 8 seconds) to be aware of traffic around you and to monitor your vehicle and trailer.

Study focusChoose safe speed, spacing, and visual search habits for commercial vehicles.

Common trapDriving at passenger-car speeds without accounting for weight, space, weather, or grade.

Speeding or driving too fast for conditions is the leading cause of fatal crashes involving large trucks.

Study focusChoose safe speed, spacing, and visual search habits for commercial vehicles.

Common trapDriving at passenger-car speeds without accounting for weight, space, weather, or grade.

The rule is 1 second per 10 feet of length, plus 1 second if going over 40 mph. For a 60-foot truck, that is 6 seconds + 1 second = 7 seconds.

Study focusChoose safe speed, spacing, and visual search habits for commercial vehicles.

Common trapDriving at passenger-car speeds without accounting for weight, space, weather, or grade.

To deal with an aggressive driver, do not engage. Get out of their way, avoid eye contact, ignore gestures, and report them if they are a severe danger.

Study focusChoose safe speed, spacing, and visual search habits for commercial vehicles.

Common trapDriving at passenger-car speeds without accounting for weight, space, weather, or grade.

Water can be used to cool down a tire fire. Using water on electrical, gasoline, or grease fires can spread the fire or cause electrocution.

Study focusApply safe loading, separation, parking, routing, and emergency-response decisions for hazmat.

Common trapChoosing a convenient action instead of the action that protects people and isolates the hazard.

Loading heavy cargo high in the trailer raises the center of gravity, making the vehicle top-heavy and much more likely to roll over in a curve or evasive maneuver.

Study focusApply safe loading, separation, parking, routing, and emergency-response decisions for hazmat.

Common trapChoosing a convenient action instead of the action that protects people and isolates the hazard.

The 'snubbing' technique involves braking firmly to 5 mph below your safe speed, then releasing them to allow cooling, repeating as necessary while the engine brake does most of the work.

Study focusChoose safe speed, spacing, and visual search habits for commercial vehicles.

Common trapDriving at passenger-car speeds without accounting for weight, space, weather, or grade.

A red triangle with an orange center on the rear of a vehicle indicates it is a slow-moving vehicle, such as a tractor or construction equipment, moving at 25 mph or less.

Study focusApply safe loading, separation, parking, routing, and emergency-response decisions for hazmat.

Common trapChoosing a convenient action instead of the action that protects people and isolates the hazard.

Mountain driving puts extreme stress on brakes. You must ensure your brakes are in perfect condition and know the route, including the location of runaway truck ramps.

Study focusApply safe loading, separation, parking, routing, and emergency-response decisions for hazmat.

Common trapChoosing a convenient action instead of the action that protects people and isolates the hazard.

You should NEVER move a severely injured person unless they are in immediate danger (like a burning vehicle). Moving them can worsen spinal or internal injuries.

Study focusApply safe loading, separation, parking, routing, and emergency-response decisions for hazmat.

Common trapChoosing a convenient action instead of the action that protects people and isolates the hazard.