Arizona CDL General Knowledge cheat sheet

Total stopping distance = perception distance + reaction distance + brake lag distance + braking distance; at 55 mph a loaded rig needs roughly the length of a football field on dry pavement.

Perception and reaction together consume about 3/4 second of travel before the brakes are applied; at 55 mph that is roughly 60 feet covered before braking begins.

The most common cause of serious truck crashes is excessive speed for conditions, especially on curves and wet or icy pavement; posted limits are maximums for ideal conditions only.

Skid recovery: stop braking, turn the steering wheel in the direction you want the front of the vehicle to go, and do not accelerate until the tires regain traction.

Following distance rule for CMVs: at least one second per 10 feet of vehicle length below 40 mph, and one additional second above 40 mph; a 60-foot rig at 55 mph needs 7 seconds.

Hydroplaning begins at highway speeds when tire pressure is low or tread is worn; ease off the accelerator and avoid hard braking until tires contact the road again.

On downgrades, select a gear low enough that engine braking holds the speed without service brakes; brake only in short, firm applications to avoid heat buildup and fade.

Railroad crossings: slow down, look and listen, ensure enough room to fully clear the tracks before crossing, and never stop on the tracks if traffic ahead is backed up.

Work zones double fines in most states; reduce speed, increase following distance, and watch flaggers and temporary lane shifts ahead of the work area.

Cargo must be secured so it cannot shift, spill, or fall; the securement system, including tiedowns and anchor points, must withstand forward force of 0.8 g and rearward and lateral force of 0.5 g of the cargo weight.

Aggregate working load limit of all tiedowns must be at least 50 percent of the cargo weight for cargo needing three or more tiedowns; for lighter loads the system must still meet the 0.8 g forward rule.

Minimum tiedown counts: one for articles 5 feet or shorter and under 1,100 pounds, two for articles longer than 5 feet but 1,100 pounds or less, and one additional tiedown for each additional 10 feet of length.

Cargo placed behind the cab must be restrained against forward movement by a headerboard, tiedowns, or the vehicle structure; the cab alone does not count as a securement device.

Front-end structure and rear-end structure rules: cargo must not extend more than 3 feet beyond the front bumper and must be marked if it extends 4 feet or more beyond the rear.

Overlength/overwidth flags: any load extending 4 feet or more beyond the rear or extending beyond the sides requires red or orange warning flags, and at night a red light is required at the extreme rear.

Cover loose aggregate, sand, or gravel with a tarp when required by state law; spilled material is a hazard and a violation that can shut the vehicle down.

Check securement within the first 50 miles of a trip and every 150 miles or 3 hours thereafter, and after any emergency stop or change in load.

Air brake system pressure must build from 85 to 100 psi within 45 seconds at fast idle; if it builds slower, the system may have a leak or a failing compressor.

Static leakage test: with the engine off and system charged, pressure loss must not exceed 3 psi in one minute for a single vehicle, or 4 psi for a combination, with brakes released.

Applied leakage test: fully apply the brakes and hold; leakage must not exceed 4 psi in one minute for a single vehicle or 6 psi for a combination.

Low-air warning must activate before pressure drops below 60 psi; the spring brakes should automatically apply when pressure falls to between 20 and 45 psi.

The alcohol evaporator or air dryer protects against moisture and ice in air lines; drain air tanks daily to remove condensation and oil.

On a vehicle with air brakes, the parking brake is spring-applied and air-released; a loss of air pressure causes the parking brake to apply automatically.

Do not fan the brakes on a long downgrade; continuous light application overheats drums and shoes and causes brake fade, so use a low gear and short, firm applications.

When the low-pressure warning sounds or the buzzer activates, stop as soon as it is safe, park, and do not drive until the system is repaired and pressure is restored.

A combination vehicle with a tractor-trailer has a shorter stopping distance and different handling than a single unit; the trailer can push the tractor forward in a hard stop, so allow more following distance.

Before driving, check the fifth wheel: it must be greased, the jaws must be locked around the kingpin, and the release handle must be in the locked position; a pull test confirms coupling.

Trailer air lines: the emergency (supply) line is typically red and the service line is blue; they must be connected cross-free and the trailer air supply valve must be pushed in to charge the trailer.

Landing gear must be fully raised after coupling; a trailer cranked too high or too low will not couple correctly and can cause the trailer to drop.

The trailer hand valve (trolley valve) is for testing trailer brakes only; do not use it for parking or for normal braking because it does not apply the tractor brakes.

When backing a combination vehicle, use the mirrors and a spotter; turn the steering wheel in the direction you want the trailer to go, and remember the trailer cuts the corner.

Check the coupling by pulling forward gently with the trailer brakes applied; if the tractor moves without resistance, the coupling is not secure.

Doubles and triples require a converter dolly to connect the first trailer to the second; the dolly has its own air lines, electrical cord, and safety chains that must be connected.

The rear trailer of a set of doubles or triples tends to sway or whip more than a single trailer; keep speed down and avoid abrupt steering or braking inputs.

When turning, the rear trailer of a set can off-track and cut the corner more sharply than the tractor; allow extra room and swing wide before the turn.

Check that the converter dolly is securely coupled to the lead trailer and that the pintle hook is latched with the safety chains attached and crossed.

Doubles and triples have more articulation points, so a hard stop can cause the rear units to push the tractor; increase following distance beyond the single-trailer rule.

Before backing a set of doubles or triples, check that the units are straight; backing a multi-trailer set is difficult and should be done slowly with a spotter.

Inspect the air lines and electrical connections between units at every stop; a disconnected line can leave the rear trailer without brakes or lights.

Liquid cargo shifts when the tank is partially full; the surge can push the vehicle forward on a stop and sideways in a turn, so keep the tank as full or as empty as practical.

A tank with baffles has compartments that reduce front-to-back surge; an unbaffled tank allows the liquid to move freely and produces the strongest surge effect.

Tank vehicles have a higher center of gravity and a higher rollover risk; slow down before curves and avoid sudden steering, especially with a partial load.

Before loading or unloading, ground the vehicle and bond the tank to the receiving container to prevent static sparks; keep the engine off and no smoking during transfer.

Check the tank's dome cover, vents, and emergency valves before driving; a loose dome cover or blocked vent can cause pressure buildup or spillage.

Tank vehicles carrying hazardous materials may require placards, and the driver must know the cargo's hazards; check the shipping papers and placards before departure.

Smooth braking and gentle acceleration reduce liquid surge; on a downgrade, use a low gear and avoid hard brake applications that amplify the surge.

A hazardous materials endorsement is required to drive a vehicle carrying placarded amounts of hazardous materials; the driver must also pass a TSA security threat assessment.

Placards must be displayed on all four sides of the vehicle for the material being carried; the placard shows the hazard class, and the shipping papers must match it.

Shipping papers must be within reach of the driver while seated, and the papers must list the proper shipping name, hazard class, ID number, and total quantity.

The emergency response information must accompany the shipping papers and include a 24-hour emergency contact number; the driver must know how to use it.

Parking rules: do not park within 5 feet of a roadway, and never park a placarded vehicle near an open flame, bridge, tunnel, or crowded place except for brief necessary stops.

Smoking and open flames are prohibited within 25 feet of a placarded vehicle during loading, unloading, or while stopped; the engine must be shut off during transfer.

If a hazardous materials incident occurs, stop, keep people away, call for help, and give the dispatcher the shipping name, class, and ID number from the papers.

The hazardous materials endorsement requires a background check and a written test; the endorsement is added to the CDL and must be renewed with the license.

A school bus driver must activate the flashing red lights and stop arm when loading or unloading students on a roadway; traffic in both directions must stop unless divided by a median.

Students must cross in front of the bus only after the driver signals them and the driver can see them; the driver must account for every student before moving.

The school bus pre-trip inspection includes checking the stop arm, flashing lights, crossing gate, emergency exits, and the child reminder system.

School buses must stop at all railroad crossings, open the door, and listen before proceeding, regardless of whether the crossing has signals.

A school bus may not exceed the posted speed limit, and many states set a lower maximum for school buses; the driver must not use a cell phone while loading or unloading.

When a school bus is stopped with red lights flashing, drivers in both directions must stop; on a divided highway, traffic on the opposite side of a median is not required to stop.

The school bus driver must use the mirrors and a spotter when backing; backing is prohibited when students are nearby unless absolutely necessary.

A passenger vehicle driver must have a passenger endorsement and a CDL; the driver is responsible for the safety of passengers and must not allow standees where prohibited.

Passengers must be seated and the aisle kept clear while the vehicle is moving; the driver must announce stops and check that all passengers have exited.

The driver must inspect the vehicle before each trip, including brakes, lights, tires, emergency exits, and fire extinguisher, and must report defects.

Passenger vehicles must stop at railroad crossings and the driver must ensure the entire vehicle clears the tracks before proceeding.

The driver may not drive more than 10 hours after 8 consecutive hours off duty, and must follow the hours-of-service rules for passenger carriers.

When loading or unloading passengers, the driver must set the parking brake, place the transmission in gear or park, and watch the mirrors for approaching traffic.

Smoking, open flames, and carrying hazardous materials are prohibited on passenger vehicles; the driver must enforce these rules.

A pre-trip inspection covers the engine compartment, walk-around items, and the in-cab controls; the driver must check fluid levels, belts, hoses, and leaks.

Walk-around items include tires, wheels, rims, lug nuts, brake and suspension components, lights, reflectors, and the coupling system on combination vehicles.

Tire checks: minimum tread depth is 4/32 inch for front tires and 2/32 inch for all other tires; look for cuts, bulges, and mismatched sizes.

Brake checks include slack adjuster travel, brake chamber condition, and air pressure buildup; the parking brake must hold the vehicle on a grade.

The in-cab inspection includes the steering wheel play, the horn, the wipers, the mirrors, the gauges, and the warning lights and buzzers.

After the inspection, the driver must sign the inspection report and note any defects; a vehicle with a serious defect must be placed out of service until repaired.

The CDL pre-trip inspection test requires the driver to point out and explain each item, not just look at it; the examiner scores the demonstration.

Before moving, complete the pre-trip inspection, adjust the seat and mirrors, fasten the seat belt, and check that the parking brake is released.

Start the engine and check the gauges; on a vehicle with air brakes, wait for pressure to build to the normal operating range before moving.

To stop smoothly, release the accelerator, apply the brakes gradually, and downshift as speed drops; do not coast in neutral.

When backing, use the mirrors and get out to check the area if unsure; back slowly and use a spotter whenever possible.

When turning, slow down before the turn, signal early, and swing wide enough to keep the rear wheels from hitting the curb or a vehicle.

On a hill, start from a stop by holding the brake, engaging the clutch or transmission, and releasing the brake as the engine begins to pull.

Use the retarder or engine brake on downgrades to control speed; do not rely on the service brakes alone, which can overheat.

Keep a space cushion around the vehicle: at least one car length per 10 mph in light traffic, and more in poor conditions or when following large vehicles.

When passing, signal early, check mirrors and blind spots, and do not return to the lane until the passed vehicle is visible in the mirror.

Large vehicles have blind spots on both sides and directly behind; if you cannot see the driver's mirrors, the driver cannot see you.

At intersections, scan left, right, and left again before entering; make eye contact with other drivers and yield to pedestrians and cyclists.

When merging, match the speed of traffic and use the acceleration lane; do not stop at the end of the on-ramp unless traffic is stopped.

Leave extra space when following motorcycles, bicycles, and pedestrians; they can stop faster than a CMV and are harder to see.

In construction zones, reduce speed, obey flaggers, and increase following distance; rear-end crashes are the most common work zone crash.

Total stopping distance = perception distance + reaction distance + brake lag distance + braking distance; at 55 mph a loaded rig needs roughly the length of a football field on dry pavement.

Perception and reaction together consume about 3/4 second of travel before the brakes are applied; at 55 mph that is roughly 60 feet covered before braking begins.

The most common cause of serious truck crashes is excessive speed for conditions, especially on curves and wet or icy pavement; posted limits are maximums for ideal conditions only.

Skid recovery: stop braking, turn the steering wheel in the direction you want the front of the vehicle to go, and do not accelerate until the tires regain traction.

Following distance rule for CMVs: at least one second per 10 feet of vehicle length below 40 mph, and one additional second above 40 mph; a 60-foot rig at 55 mph needs 7 seconds.

Hydroplaning begins at highway speeds when tire pressure is low or tread is worn; ease off the accelerator and avoid hard braking until tires contact the road again.

On downgrades, select a gear low enough that engine braking holds the speed without service brakes; brake only in short, firm applications to avoid heat buildup and fade.

Railroad crossings: slow down, look and listen, ensure enough room to fully clear the tracks before crossing, and never stop on the tracks if traffic ahead is backed up.

Work zones double fines in most states; reduce speed, increase following distance, and watch flaggers and temporary lane shifts ahead of the work area.