Commercial Driver's License Guide

A pre-trip inspection is the driver responsibility that confirms key systems are safe before operating the vehicle.

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.

Wet roads reduce traction and increase stopping distance, so the safer adjustment is slower speed and more 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.

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.

Alcohol first affects judgment and self-control. For commercial drivers, it is illegal to operate a CMV with a BAC of 0.04% or higher, not 0.08%.

Study focusUnderstand state-specific CDL requirements, handbook notes, and licensing context.

Common trapUsing generic CDL knowledge without checking state-specific requirements.

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.

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.

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.

Following too closely (tailgating) severely reduces your reaction time and stopping distance, making it a leading cause of crashes.

Study focusUnderstand state-specific CDL requirements, handbook notes, and licensing context.

Common trapUsing generic CDL knowledge without checking state-specific requirements.