Illinois CDL General Knowledge cheat sheet

Pre-trip inspection covers three areas: engine compartment (fluids, belts, hoses, steering, exhaust, battery), walk-around (lights, tires, wheels, mud flaps, frame, coupling devices), and in-cab (gauges, controls, mirrors, horn, wipers, emergency equipment).

Check tire tread depth minimum 4/32 inch on front steering tires and 2/32 inch on all other tires; inspect for cuts, bulges, and recaps separated from the casing.

Test service brakes three ways: applied-pressure test (no air loss above limits), leakage rate test (static), and the low-air warning device must activate before pressure drops below 60 psi.

For air brake vehicles, the governor must cut out and the system must build from 85 to 100 psi within 45 seconds at fast idle; the safety valve releases near 150 psi.

Check coolant level only when the engine is cold; never open a hot pressurized radiator cap because scalding coolant can spray out.

Inspect the fifth wheel, locking jaws, and safety latch; tug-test the trailer after coupling by pulling gently against the locked trailer brakes.

After any break of more than three hours or a change of duty status, complete a new inspection; en route, stop and re-check cargo, tires, and lights at least every 150 miles or 3 hours.

Mirrors must show the tires touching the ground and a full view down both sides; adjust before driving, not while moving.

Use the steering method that keeps both hands on the wheel; at highway speed, small steering inputs produce large lateral movement, so avoid overcorrecting.

Back only when necessary and use a helper or get out and check; when backing, back toward the driver's side so the trailer or vehicle moves to the left and stays in view.

Start braking well before a stop; a loaded vehicle needs far more stopping distance than an empty one, and brake fade reduces braking on long downgrades.

When a front tire blows out, hold the wheel firmly, stay off the brakes, and let the vehicle slow gradually before pulling off the road.

Accelerate and brake smoothly to keep the load from shifting; abrupt steering at speed can cause a rollover, especially with a high center of gravity.

Use four-way flashers when driving slowly enough to be a hazard (below about 40 mph on a highway) so faster traffic can see you.

Turn signals must be given at least 100 feet before a turn in urban areas and 300 feet on highways; cancel them after the turn.

A manual transmission must be shifted so engine speed matches road speed; do not coast with the clutch in or in neutral, which reduces control and braking.

Double-clutching: press clutch, shift to neutral, release clutch, press clutch again, then shift into the next gear. It is required when shifting a non-synchronized transmission.

Shift down before a long downgrade and use engine braking; do not ride the brakes, which causes overheating and fade.

Do not skip gears when downshifting a heavy vehicle unless you match engine and road speed; skipping can over-speed the engine or damage the drivetrain.

The tachometer should stay in the green or operating range; upshift before reaching the governed rpm and downshift before the engine lugs.

On a steep upgrade, shift down before the engine loses power; waiting until the engine lugs may force a shift while the vehicle is losing speed.

Scan 12 to 15 seconds ahead of the vehicle; at highway speed that is roughly a quarter mile, giving time to react to developing hazards.

Look for clues: brake lights, turn signals, swerving vehicles, road signs, and pedestrians near the curb signal a possible hazard before it becomes one.

A hazard is any road condition or other road user that is a possible danger; classify hazards as immediate or distant so you can plan an escape route.

Check mirrors every 5 to 8 seconds and before changing lanes, slowing, or turning; know what is beside and behind you at all times.

Watch for distracted drivers, vehicles drifting in lanes, and drivers who fail to signal; assume they may not see you and create space.

At night or in poor visibility, look for reflective markings, road-edge lines, and headlights of oncoming vehicles to judge lane position.

Use the high-beam headlights when legal and dim them for oncoming traffic; look toward the right edge of your lane to avoid glare.

Signal turns and lane changes at least 100 feet in advance in cities and 300 feet on highways; signal even when you think no one is there.

Use the horn only to warn others of danger, not to express annoyance; a light tap can alert a driver drifting toward you.

Tap the brakes lightly to warn following drivers you are slowing, especially before a stop or when traffic backs up ahead.

Four-way flashers warn others when you are stopped or moving slowly; use them when stopped on the shoulder or in a work zone.

At night, flash high beams to signal your presence, but never use them to blind oncoming drivers; dim them within 500 feet of oncoming vehicles and 200 feet when following.

Make eye contact with pedestrians and other drivers when possible; a wave or hand signal can clarify your intention when signals are ambiguous.

Keep headlights, taillights, and reflective tape clean so other drivers can see you; dirty lenses cut visibility significantly.

Stopping distance = perception distance + reaction distance + braking distance; total stopping distance grows with the square of speed, so doubling speed roughly quadruples braking distance.

At 55 mph a loaded tractor-trailer needs about the length of a football field or more to stop; wet or icy roads increase that distance substantially.

The speed limit is a maximum for ideal conditions; reduce speed in rain, fog, snow, curves, and heavy traffic so you can stop within the distance you can see.

Use the posted speed as a guide but drive at a speed that lets you stop within the distance you can see ahead, especially at night or in fog.

On a downgrade, select a gear low enough that the engine and brakes together hold your speed; do not rely on brakes alone.

Ramp and curve advisory speeds are posted for a reason; a high center of gravity vehicle can roll over if taken too fast.

When entering a curve, slow down before the curve and accelerate gently after the midpoint; braking in the curve reduces stability.

Follow at least one second per 10 feet of vehicle length at speeds under 40 mph; above 40 mph add one second, so a 60-foot vehicle needs about 7 seconds.

Maintain at least one car length of space per 10 mph of speed in front, and keep a cushion on both sides and behind.

When following a vehicle, use a fixed object as a check: count seconds from when the vehicle ahead passes it until you pass it.

Leave space to stop when traffic ahead slows suddenly; if a driver cuts in front of you, drop back to restore your following distance.

At intersections, stop far enough back to see the rear tires of the vehicle ahead touching the road; this leaves room to steer around it.

When passing, do not return to the right lane until you can see the passed vehicle's headlights in your mirror.

Leave space around your vehicle on all sides; a space cushion gives you room to maneuver if another driver makes a mistake.

Night driving reduces visibility, so slow down and increase following distance; never drive faster than you can stop within the distance your headlights light up.

Use low beams when within 500 feet of oncoming traffic and within 200 feet when following another vehicle; high beams are for open road.

At night, look to the right edge of your lane rather than directly at oncoming headlights to avoid glare and stay in lane.

Fatigue is a major night hazard; stop and rest when drowsy, and avoid driving during the hours when you would normally sleep.

Clean headlights, windshield, and mirrors before night driving; dirt and film scatter light and reduce visibility.

Use interior lights sparingly; they reflect on the windshield and reduce your ability to see the road.

Watch for pedestrians and cyclists at night; they are hard to see, so scan the road edges and crosswalks carefully.

Before winter, check antifreeze strength, battery, tires, wipers, heater/defroster, and carry chains, a shovel, sand, and warm clothing.

On ice and snow, reduce speed and increase following distance; braking distance can be many times longer than on dry pavement.

If you skid, take your foot off the accelerator and steer in the direction you want the front of the vehicle to go; do not brake hard.

Use gentle brake and accelerator inputs; sudden movements can cause a loss of traction, especially on bridges and shaded areas that freeze first.

Use chains only where required or permitted; install them on the drive tires and check tension after driving a short distance.

When stopped in snow, clear snow from the exhaust pipe before starting the engine to prevent carbon monoxide from entering the cab.

Watch for black ice on bridges, overpasses, and shaded curves; these surfaces freeze before the rest of the road.

Heat increases tire pressure and can cause blowouts; check tires when cold and inspect for tread separation, cuts, and bulges.

Engine overheating can be caused by a low coolant level, a broken fan belt, or a faulty thermostat; pull over and let the engine cool before opening the radiator.

Hot weather thins engine oil and stresses the cooling system; check oil and coolant levels frequently on long trips.

Asphalt can soften in extreme heat and become slippery; reduce speed and avoid sudden braking on soft pavement.

Watch for tire failure signs: thumping, vibration, or a sudden pull; hold the wheel and slow gradually if a tire blows.

Carry extra water and check the air conditioner and cooling system before a trip; heat exhaustion affects driver judgment.

Before a long downgrade, check brakes, select a low gear, and use engine braking; do not ride the brakes, which causes overheating and fade.

The rule for downgrades: use the same gear going down that you would need to climb the grade; if you have to brake hard, you are in too high a gear.

Watch the engine temperature and use a lower gear if brakes begin to fade; pull over and let brakes cool if needed.

On upgrades, shift down before the engine loses power; a loaded vehicle can lose speed quickly on a steep grade.

Use turnouts to let faster traffic pass; mountain roads often have narrow shoulders and limited passing zones.

Watch for changing weather and road conditions at elevation; ice and snow can appear on mountain passes even in mild seasons.

Keep the vehicle centered in your lane on curves; a high center of gravity vehicle can drift or roll if taken too fast.

A hazardous materials endorsement is required to drive a vehicle carrying placarded amounts of hazardous materials; a background check and knowledge test are required.

Placards must be displayed on all four sides of a vehicle carrying hazardous materials in reportable quantities; the placard matches the hazard class.

Shipping papers must be within reach while driving and must include the proper shipping name, hazard class, UN number, and quantity.

Never smoke or use open flame near hazardous materials; keep the engine off during loading and unloading unless required for operation.

Park a placarded vehicle away from bridges, tunnels, and populated areas; attend the vehicle at all times when required.

In an emergency, call for help, keep people away, and follow the emergency response information on the shipping papers; do not attempt to handle a leak unless trained.

Some materials require route restrictions, tunnel bans, or escort vehicles; check the regulations before planning a trip.

Cargo must be secured so it cannot shift, spill, or fall; use tiedowns, straps, and blocking, and check the load after the first 50 miles and every 150 miles or 3 hours.

The maximum weight limits: 20,000 pounds on a single axle, 34,000 pounds on a tandem axle group, and 80,000 pounds gross vehicle weight without a permit.

Cargo must not extend more than 3 feet beyond the front of the vehicle or more than 4 feet beyond the rear; flag or mark overhangs.

Distribute weight evenly and keep the center of gravity low; an unbalanced load can cause a rollover or loss of steering control.

Cover loads that could blow off or spill; loose material must be tarped or secured so it does not fall onto the road.

Check the load and tiedowns before driving, after the first 50 miles, and every 150 miles or 3 hours thereafter; retighten as needed.

A load that shifts can change axle weight and handling; stop and redistribute if the vehicle feels unstable.

Safety equipment required: fire extinguisher, spare fuses, warning triangles or reflective devices, and a first aid kit for some vehicles; know where they are and how to use them.

Use warning devices (triangles or flares) when stopped on a highway: place them behind the vehicle to warn traffic, farther back at higher speeds.

Seat belts must be worn by the driver and passengers; they reduce the risk of injury and are required by law.

Check the fire extinguisher pressure gauge and know the PASS method: Pull the pin, Aim at the base, Squeeze the handle, Sweep side to side.

Never leave the scene of an accident; stop, render aid if trained, exchange information, and report the crash as required.

Keep the vehicle's emergency equipment accessible and inspect it during the pre-trip; a missing or expired extinguisher is a violation.

Report any defect that affects safe operation and do not drive an unsafe vehicle; the driver is responsible for the vehicle's condition.