Arkansas CDL General Knowledge Test flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Total stopping distance

The sum of perception distance, reaction distance, brake lag distance, and braking distance. At 55 mph it is roughly 419 feet for a loaded tractor-trailer.

Perception distance

The distance traveled from the moment a hazard is seen until the brain recognizes it. At 55 mph this is about 60 feet.

Reaction distance

The distance traveled from recognizing a hazard until the foot hits the brake pedal. At 55 mph this is about 61 feet.

Brake lag distance

The distance traveled while the air pressure travels through the system before the brakes apply. At 55 mph this is about 32 feet.

Following distance rule

Use one second for each 10 feet of vehicle length at speeds under 40 mph, and add one second at speeds above 40 mph.

Aggregate working load limit

The sum of the working load limits of all tiedown assemblies used to secure cargo to the vehicle.

Tiedown requirement

Articles 5 feet or shorter and 1,100 lb or less need one tiedown. Longer or heavier articles need at least two tiedowns.

Cargo extension marking

Cargo extending more than 4 feet beyond the rear must be marked with a red flag in daylight and a red light at night.

Bulkhead

A structure placed behind the cab to stop cargo from shifting forward and crushing the cab or driver.

Air brake build-up

With the engine at fast idle, air pressure must build from 85 to 100 psi within 45 seconds.

Leak test

With the engine off and parking brake released, pressure should not drop more than 3 psi in one minute for a single vehicle, or 4 psi for a combination.

Low-air warning

The warning must activate before pressure drops below 60 psi. The spring brakes apply between 20 and 45 psi.

Safety valve setting

The safety valve opens at 150 psi to release excess pressure. The governor cuts out at about 125 psi and cuts in at about 100 psi.

Slack adjuster check

With the brake released, the slack adjuster should not move more than 1 inch. More than 1 inch means the brakes need adjustment.

Tractor protection valve

A valve that keeps air in the tractor if the trailer breaks away. It closes at about 20 to 45 psi.

Fifth wheel check

Perform a tug test, visually check that the jaws are closed, and confirm the locking lever is secured before driving.

Off-tracking

The tendency of the rear wheels of a combination vehicle to follow a path inside the front wheels during a turn.

Trailer air lines

The emergency (supply) line is red; the service line is blue. Crossing them can prevent the trailer brakes from working.

Pre-trip inspection parts

The three main parts are the engine compartment check, the walk-around check, and the in-cab check.

Tire tread depth

Front tires must have at least 4/32 inch of tread; all other tires must have at least 2/32 inch.

Steering free play

The steering wheel should not move more than 10 degrees (about 2 inches) before the front wheels begin to move.

Stab braking

For vehicles without ABS, apply the brakes fully, release when the wheels lock, and reapply when they roll again.

Controlled braking

For vehicles with ABS, squeeze and hold the brake pedal firmly without pumping it.

Retarder use

An engine brake or retarder helps control speed on downgrades without continuous use of the service brakes.

Double clutching

For non-synchronized transmissions: clutch in, shift to neutral, clutch out, clutch in, shift to gear.

Backing with a spotter

Use a spotter and check both mirrors. If you lose sight of the spotter, stop immediately.

High beam dimming

Dim high beams within 500 feet of an oncoming vehicle and within 200 feet when following another vehicle.

Turn signal distance

Signal at least 100 feet before a turn. Use hand signals if the turn signals fail.

Mirror check interval

Check the mirrors every 5 to 8 seconds and adjust them before driving.

Wet road speed

Reduce speed by about one-third on wet roads and by about one-half on packed snow. Slow to a crawl on ice.

Passing time

Allow at least 10 seconds to complete a pass, and do not return to the lane until you can see the passed vehicle's headlights.

Tire blowout response

Hold the steering wheel firmly and avoid hard braking. Let the vehicle slow down gradually before pulling off the road.

Warning triangle placement

Place one triangle 10 feet behind the vehicle, one 100 feet behind, and one 100 feet ahead on a two-way road.