CDL Alcohol Limit for Drivers

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.

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.

Engine retarders (Jake brakes) apply strong braking force to the drive wheels only. On slippery surfaces, this sudden braking force can cause the drive wheels to lose traction, leading to a dangerous skid.

Study focusRespond safely to hazards, emergencies, traction loss, and unsafe conditions.

Common trapReacting late or using sudden braking/steering when controlled action is safer.

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.

Eating, using a phone, or reading while driving are major physical and cognitive distractions that take your eyes, hands, and mind away from the critical task of driving.

Study focusRespond safely to hazards, emergencies, traction loss, and unsafe conditions.

Common trapReacting late or using sudden braking/steering when controlled action is safer.

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.

On a two-lane road carrying traffic in both directions, place warning devices within 10 feet of the front or rear corners, about 100 feet behind, and about 100 feet ahead of the vehicle.

Study focusRespond safely to hazards, emergencies, traction loss, and unsafe conditions.

Common trapReacting late or using sudden braking/steering when controlled action is safer.

Federal regulations require that emergency warning devices (like reflective triangles) be placed within 10 minutes of stopping on the shoulder or traveled portion of the road.

Study focusRespond safely to hazards, emergencies, traction loss, and unsafe conditions.

Common trapReacting late or using sudden braking/steering when controlled action is safer.

To recover from hydroplaning, release the accelerator and push in the clutch. Do not use the brakes, as this can cause the wheels to lock and result in a skid.

Study focusRespond safely to hazards, emergencies, traction loss, and unsafe conditions.

Common trapReacting late or using sudden braking/steering when controlled action is safer.

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.

Black ice is a thin layer of clear ice. Because it is clear, you can see the dark asphalt underneath, making the road appear wet rather than icy.

Study focusRespond safely to hazards, emergencies, traction loss, and unsafe conditions.

Common trapReacting late or using sudden braking/steering when controlled action is safer.

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.