NJ CDL General Knowledge cheat sheet

A pre-trip inspection must cover the engine compartment, cab and controls, lights, walk-around items, and brake check before the vehicle moves.

CDL pre-trip inspection has three official parts: the engine compartment, the exterior walk-around (front, sides, rear), and the in-cab inspection.

The three-point mount and dismount rule: face the vehicle, keep three points of contact (two hands and one foot or two feet and one hand) on the handholds and steps at all times.

Air brake pre-trip: build pressure to governor cut-out, then check that the compressor re-engages near 100 psi and that the low-air warning activates near 60 psi.

Static leak test: with the engine off and full pressure, apply the brake pedal and hold 1 minute; leakage must not exceed 3 psi for a single vehicle or 4 psi for a combination.

Applied leak test: with a fully charged system and engine off, hold the brake pedal for 1 minute; a loss of more than 3 psi (single) or 4 psi (combination) indicates a leak.

Slack adjuster check: with the parking brake released and the service brake applied, the pushrod should move no more than about 1 inch; 2 inches or more means the brakes are out of adjustment.

The in-cab inspection covers seat belt, horn, gauges, mirrors, windshield wipers, heater/defroster, emergency equipment, and warning lights.

Double-clutching: press the clutch, shift to neutral, release the clutch, press the clutch again, shift into the next gear, then release.

Floating gears (shifting without the clutch) is legal only if the transmission is designed for it and the driver matches engine rpm to road speed.

Downshift before a downgrade; do not shift while descending a steep grade because you may not be able to re-engage the gear.

Backing rule: always back toward the driver's side (left) and use a helper or get out and check behind the vehicle.

When backing, if you lose sight of the helper in the mirrors, stop immediately until the helper is visible again.

Right turns: swing wide enough to keep the rear wheels from off-tracking over the curb or into traffic; watch the right mirror for the trailer or rear wheels.

Off-tracking: the rear wheels of a long vehicle follow a shorter path than the front wheels, so the vehicle cuts the corner on turns.

Turn signals must be given at least 100 feet before a turn in urban areas and at least 300 feet before a turn in rural areas.

Aim your eyes high and look 12-15 seconds ahead of the vehicle; at highway speed that is about a quarter mile.

Use the 4-6 second following distance rule for a loaded tractor-trailer at highway speed; 1 second per 10 feet of vehicle length above 40 mph.

If a vehicle passes you, drop back and re-establish your following distance so you can see around it; do not stay in its blind spot.

Signal every lane change, turn, and stop; cancel the signal after completing the maneuver.

Use four-way flashers when driving below 45 mph (or the posted minimum) and when stopped or parked on the shoulder.

Tap the brakes lightly to warn following drivers of a slowdown when you cannot see them well or when traffic is stopping suddenly.

Communicate with the horn only to warn others of danger, not to express frustration; the horn is a safety device.

Mirror checks should be frequent and systematic: check both mirrors every 5-8 seconds and before any lane change or turn.

Posted speed limits are for ideal conditions; reduce speed for rain, snow, fog, curves, heavy traffic, and darkness.

The speed limit is the maximum lawful speed, not a target; a driver must adjust to the road, weather, and load.

Stopping distance = perception distance + reaction distance + braking distance.

Total stopping distance for a loaded tractor-trailer at 55 mph is roughly the length of a football field (about 300 feet) or more.

Braking distance increases with the square of speed: doubling speed quadruples braking distance.

Use the 1-second-per-10-feet rule for following distance at speeds above 40 mph; at 55 mph a 60-foot combination needs about 6 seconds.

On downgrades, select a gear low enough that the engine and brakes control speed without riding the brakes.

Space to the sides: keep a lane open or a cushion next to you; do not drive alongside another vehicle where you cannot see its mirrors.

At night, use low beams in fog, rain, snow, and when following another vehicle within 200 feet; use high beams on open road when legal.

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

When a vehicle with bright lights approaches, look toward the right edge of your lane to avoid glare.

Fog rule: slow down, use low beams, and increase following distance; do not stop on the traveled portion of the road.

Ice and snow: reduce speed, avoid sudden braking and steering, and allow at least double the normal following distance.

Hydroplaning occurs when tires ride on a film of water; it can happen at speeds as low as 30-35 mph on wet roads.

To recover from hydroplaning, ease off the accelerator and avoid braking hard; let the tires regain contact with the road.

High winds: reduce speed, grip the wheel firmly, and be alert for sudden gusts when passing bridges, overpasses, and large vehicles.

The Smith System five keys: aim high, get the big picture, keep your eyes moving, leave yourself an out, and make sure others see you.

A hazard is anything that could require a change in speed or direction; scan 12-15 seconds ahead to identify it early.

Escape route: always keep at least one open path (an out) so you are not boxed in by traffic.

Tire blowout: hold the steering wheel firmly, keep the vehicle straight, ease off the accelerator, and do not brake hard until the vehicle is under control.

Brake failure: pump the brakes, downshift, use the emergency/parking brake gradually, and look for an escape ramp or safe off-road area.

Engine fire: stop, shut off the engine, get everyone out, and move away from the vehicle; do not open the hood if flames are visible.

When a vehicle is stalled on railroad tracks, get out and run away from the tracks at an angle toward the approaching train.

Emergency stopping on a highway: pull as far off the road as possible, turn on four-way flashers, and place reflective triangles behind the vehicle.

Skid recovery: steer in the direction you want the vehicle to go, ease off the accelerator, and avoid hard braking until the tires regain traction.

Rear-wheel skid: the rear of the vehicle slides sideways; steer into the skid and do not brake hard.

Front-wheel skid: the vehicle will not turn; ease off the accelerator and steer straight until the tires regain grip.

ABS does not shorten stopping distance on all surfaces, but it prevents wheel lockup and allows steering during hard braking.

With ABS, press the brake pedal firmly and hold it; do not pump the brakes.

Engine retarders (Jake brakes) are prohibited in many areas and should be turned off on slippery surfaces to avoid drive-wheel skids.

The air brake system uses a compressor, governor, reservoirs, and a safety valve that releases at about 150 psi.

The parking brake (spring brake) applies automatically when air pressure drops too low; a low-air warning activates near 60 psi.

Federal gross vehicle weight limit on the Interstate System: 80,000 pounds.

Single-axle weight limit: 20,000 pounds; tandem-axle limit: 34,000 pounds on the Interstate System.

Cargo securement requires at least one tiedown for every 10 feet of cargo length, and a minimum of two tiedowns for any load longer than 5 feet.

Aggregate working load limit of all tiedowns must be at least 50% of the cargo weight.

Cargo must not extend more than 3 feet beyond the front of the vehicle or more than 4 feet beyond the rear, unless flagged.

Rear overhang beyond 4 feet must be marked with a red or orange flag at least 12 inches square during daylight.

Cargo must be secured so it cannot shift, leak, or fall; check tiedowns and cargo within the first 50 miles and every 150 miles or 3 hours thereafter.

Axle weight limits are set by the manufacturer and by state law; exceeding them can cause tire failure and loss of control.

Tractor-trailer coupling: back under the trailer slowly, check that the kingpin is locked, and tug-test the tractor forward with the trailer brakes set.

Fifth-wheel jaws must be closed around the kingpin; check the release handle is in the locked position and the safety latch is engaged.

Connect the air lines (red emergency/blue service) and electrical cord, then check that trailer air pressure builds and the trailer brakes release.

Trailer hand valve (spike) is used only for testing trailer brakes, not for parking or normal stopping.

Air brake system components: compressor, governor, reservoir tanks, foot valve, slack adjusters, chambers, and spring brakes.

The air compressor is governed to cut out near 125 psi and cut in near 100 psi; the safety valve releases at about 150 psi.

If air pressure drops below 60 psi, the low-air warning buzzer/light activates and the spring brakes will begin to apply.

Before driving, check that the air pressure builds from 85 to 100 psi within 45 seconds at normal engine rpm.

A CDL holder must be at least 21 years old to drive interstate in a commercial motor vehicle and at least 18 for intrastate operation.

The 11-hour driving limit: a driver may drive no more than 11 hours after 10 consecutive hours off duty.

The 14-hour rule: a driver may not drive beyond the 14th consecutive hour after coming on duty, regardless of breaks.

The 30-minute break rule: a driver must take a 30-minute break after 8 cumulative hours of driving without at least a 30-minute interruption.

The 60/70-hour rule: a driver may not drive after 60 hours on duty in 7 consecutive days or 70 hours in 8 consecutive days.

A driver must keep a record of duty status (logbook/ELD) for each 24-hour period and retain records for 6 months.

The driver vehicle inspection report (DVIR) is required daily for each vehicle operated; defects must be reported and repaired before driving.

A driver must report any traffic violation (other than parking) to the employer within 30 days and provide a copy of the citation.

CDL BAC limit is 0.04% - half the 0.08% limit for non-commercial drivers - and a violation results in CDL disqualification.

Refusing a required alcohol or drug test results in CDL disqualification for at least 1 year for a first offense.

A first DUI conviction in a CMV disqualifies the driver for at least 1 year; a second conviction disqualifies for life.

Drivers must submit to pre-employment, random, reasonable-suspicion, post-accident, return-to-duty, and follow-up drug and alcohol testing.

Post-accident testing is required when there is a fatality, or when the driver is cited and someone is injured or a vehicle is towed.

Controlled substances (including marijuana, even where state-legal) are prohibited for CDL drivers under federal rules.

Alcohol is metabolized at about one drink per hour; coffee, cold showers, and exercise do not speed up sobriety.

Personal safety: lock the cab, park in well-lit areas, and report suspicious activity; do not pick up hitchhikers.