Maine CDL General Knowledge flashcards

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

Pre-trip inspection areas

Three areas: engine compartment, cab and controls, and exterior walk-around covering front, sides, rear, lights, and couplings.

Front tire tread minimum

At least 4/32 inch on front tires and 2/32 inch on all other tires; recaps are not allowed on front wheels.

Static air leak limit

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

Total stopping distance formula

Perception distance plus reaction distance plus brake lag distance plus braking distance. At 55 mph a loaded tractor-trailer needs about 419 feet on dry pavement.

Off-tracking definition

The rear wheels follow a shorter path than the front wheels in a turn; a tractor-trailer can off-track as much as one lane width.

Backing rule

Use a helper whenever possible, back toward the driver's side (left) when practical, and stop immediately if the helper is out of sight.

Double-clutch procedure

Press clutch, shift to neutral, release clutch, press clutch again, then shift into the next gear while matching engine speed.

Downgrade gear selection

Choose a gear low enough that engine braking holds speed without continuous service brake use; do not ride the brakes.

Coasting prohibition

Never coast with the clutch depressed or in neutral; you lose engine braking and the ability to accelerate out of a hazard.

Turn signal distance

Signal continuously for at least the last 100 feet before a turn in business or residential areas, and cancel after completing the maneuver.

High beam dimming distances

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

Eye lead time

Look at least 12-15 seconds ahead in city driving and 20-25 seconds on the highway to spot hazards early.

Following distance rule

One second for each 10 feet of vehicle length below 40 mph, plus one second above 40 mph. A 60-foot vehicle at 40 mph needs 6 seconds.

Space to the sides

Avoid driving beside another vehicle; keep at least one lane of space on each side when possible, and more on the right.

Tailgater response

Increase your own following distance ahead so you can brake gradually, and change lanes to let the tailgater pass.

Tire blowout response

Hold the wheel firmly, keep the vehicle straight, ease off the accelerator, and brake gently once the vehicle is under control.

Skid recovery technique

Steer in the direction you want the front of the vehicle to go, ease off the accelerator, and avoid hard braking until traction returns.

Runaway truck ramp use

If you lose braking on a downgrade, steer straight into the ramp and do not brake hard on the gravel.

Headlight sight distances

Low beams show about 160 feet and high beams about 350 feet; reduce speed so you can stop within the illuminated distance.

Fog driving rule

Slow down, use low beams or fog lights, increase following distance, and be ready to stop; high beams reflect off fog.

Hydroplaning response

Ease off the accelerator, do not brake hard, and steer straight until the tires regain contact with the road.

Minimum tiedowns

One for cargo up to 5 feet and 1,100 pounds; two for cargo over 5 feet but under 10 feet; three for cargo 10 feet or longer.

Tiedown working load limit

The aggregate working load limit of all tiedowns must be at least 50% of the cargo weight, with one tiedown every 10 feet.

Maximum cargo height

Generally 13 feet 6 inches in most states, though some western states allow 14 feet; check the route for low bridges.

Standee line rule

Do not allow passengers to stand forward of the standee line or in the aisle while the bus is moving.

Bus evacuation steps

Stop the bus, set the parking brake, shut off the engine, open the exits, and lead passengers to a safe location away from traffic.

Governor cut-in and cut-out

The governor cuts the compressor in at about 100 psi and out at about 125 psi; the safety valve releases at about 150 psi.

Low pressure warning

The warning must activate before pressure drops below 60 psi; spring brakes apply when pressure drops to about 20-45 psi.

Slack adjuster check

With brakes released, the push rod should move no more than 1 inch by hand; with brakes applied, the push rod angle should be about 90 degrees.

Tug test purpose

After coupling, pull forward gently with the trailer brakes locked to confirm the kingpin is locked in the fifth wheel.

Trailer air line order

Connect the emergency (supply) line first, then the service line; check that the lines are not crossed or kinked.

Hours of service limits

11 hours driving after 10 consecutive hours off duty, a 14-hour on-duty window, a 30-minute break after 8 hours of driving, and a 60/70-hour limit in 7/8 days.

CDL alcohol limit

A commercial driver must not operate with a blood alcohol concentration of 0.04 or higher, which is lower than the 0.08 limit for non-commercial drivers.