ND CDL General Knowledge cheat sheet

Class A = combination vehicle with GCWR of 26,001 lb or more, towed unit over 10,000 lb; Class B = single vehicle 26,001 lb or more, or towing 10,000 lb or less; Class C = 26,000 lb or less carrying 16+ passengers or placarded hazmat.

Pre-trip inspection order: engine compartment (fluids, belts, hoses, steering, exhaust, leaks) → walk-around lights and tires → brake test (air buildup, leakage, service and parking brake).

Air brake check sequence: build to governor cut-out, key off, verify no more than 3 psi loss in one minute (single vehicle) and no more than 4 psi (combination); then apply service brake and hold 5 minutes.

Following distance at speeds under 40 mph: one second per 10 feet of vehicle length plus one extra second; a 60-foot vehicle at 40 mph needs 7 seconds.

Stopping distance = perception distance + reaction distance + brake lag distance + braking distance; total stopping distance at 55 mph for a loaded rig is roughly the length of a football field.

Speed and space rules: reduce speed by at least 1/3 on wet roads, by half on packed snow, and crawl on ice; never drive faster than conditions allow regardless of the posted limit.

Downgrade rule: select a gear low enough that engine braking holds the speed without using the brakes, and use the brakes only lightly and intermittently - never fan or ride them.

Railroad crossing rule: stop within 15 to 50 feet of the nearest rail when carrying placarded hazmat, passengers, or when a stop is posted; never stop on the tracks.

Alcohol limits: 0.04% BAC for holders of a CDL, 0.02% for drivers under 21, and 0.08% for other drivers; refusal to test triggers a one-year CDL disqualification.

Air pressure must build from 85 to 100 psi within 45 seconds at fast idle; the low-pressure warning must activate before pressure drops below 60 psi.

Governor cut-out is typically 120–140 psi and cut-in about 20–25 psi lower; if pressure never reaches cut-out, the compressor or governor is faulty.

Static leakage limits: 3 psi per minute for a single vehicle and 4 psi per minute for a combination, tested with the engine off and the system fully charged.

Applied leakage limit: with the service brake fully applied and held, loss must not exceed 4 psi per minute; release the brake before rechecking.

The spring (parking) brake applies automatically when pressure falls to roughly 20–45 psi; this is why a slow leak can lock the wheels.

The safety valve on the air tank opens near 150 psi to protect the system; a valve that vents in normal operation indicates a faulty governor or compressor.

Brake lag is the time between pressing the pedal and the brakes applying at the wheels - about 0.4 second at 55 mph, adding roughly 32 feet to stopping distance.

A slack adjuster pushrod travel beyond the adjustment limit means the brakes are out of adjustment; the vehicle must be placed out of service.

Drain air tanks daily to remove moisture and oil; the supply tank is drained first, and the drain cocks are closed before driving.

Tractor protection valve: the trailer air supply (red) knob controls air to the trailer and closes automatically if a trailer breaks away; the trailer hand valve (johnson bar) is for testing only, never for parking or normal stopping.

Tug test: after coupling, pull gently against the locked trailer brakes and check that the trailer does not move, then release and verify the fifth-wheel jaws are closed around the kingpin.

Fifth-wheel inspection: check the mounting bolts, that the jaws are locked, the release lever is secured, and the locking pin is in place; a gap between the apron and the fifth wheel is a defect.

Trailer air lines: the emergency (supply) line is red and the service line is blue; crossed or reversed lines cause the trailer brakes to stay applied or fail to release.

Off-tracking: the rear wheels of a combination follow a shorter path than the front; at a 90-degree turn the rear of a 55-foot trailer can swing out up to 5 feet beyond the path of the tractor.

Swing-out rule: the rear of the trailer swings wide in the opposite direction of the turn, so check both mirrors and the outside corner before turning.

Brake test for a combination: with the trailer brakes released and the tractor brakes applied, the combination must not move; then test the trailer brakes alone.

Rollover risk rises with a high center of gravity; posted curve speeds are for cars, so a loaded combination should enter curves well below the posted speed.

Coupling order: secure the trailer, back under slowly, listen for the click, tug test, connect air lines and electrical cord, then raise the landing gear.

Placards are required for 1,001 lb or more aggregate gross weight of a hazard class in one vehicle, and any quantity of Table 2 materials; the placard matches the hazard class, not the individual material.

The shipping paper must describe the hazard in order: proper shipping name, hazard class or division, UN/NA identification number, and packing group (e.g., Gasoline, 3, UN1203, PG II).

The emergency response information must accompany the shipping paper, and the shipping paper must be kept within reach of the driver, in a pocket or holder near the door.

A hazardous materials endorsement requires a TSA security threat assessment; the endorsement is valid for the same period as the license and must be renewed with a new assessment.

Parking rules: never park within 5 feet of a roadway, and stay at least 300 feet from open flames, bridges, tunnels, and heavily populated areas unless the shipper directs otherwise.

The ERG guide number and the four-digit UN number are used by responders; the driver should know the material's class, the placard, and the emergency phone number on the shipping paper.

Cargo securement for hazmat: packages must be blocked and braced to prevent movement, and leaking packages must not be loaded or transported.

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

A placarded vehicle must stop before every railroad crossing, and the driver must look and listen before proceeding; never stop on the tracks.

Class A = combination vehicle with GCWR of 26,001 lb or more, towed unit over 10,000 lb; Class B = single vehicle 26,001 lb or more, or towing 10,000 lb or less; Class C = 26,000 lb or less carrying 16+ passengers or placarded hazmat.

Pre-trip inspection order: engine compartment (fluids, belts, hoses, steering, exhaust, leaks) → walk-around lights and tires → brake test (air buildup, leakage, service and parking brake).

Air brake check sequence: build to governor cut-out, key off, verify no more than 3 psi loss in one minute (single vehicle) and no more than 4 psi (combination); then apply service brake and hold 5 minutes.

Following distance at speeds under 40 mph: one second per 10 feet of vehicle length plus one extra second; a 60-foot vehicle at 40 mph needs 7 seconds.

Stopping distance = perception distance + reaction distance + brake lag distance + braking distance; total stopping distance at 55 mph for a loaded rig is roughly the length of a football field.

Speed and space rules: reduce speed by at least 1/3 on wet roads, by half on packed snow, and crawl on ice; never drive faster than conditions allow regardless of the posted limit.

Downgrade rule: select a gear low enough that engine braking holds the speed without using the brakes, and use the brakes only lightly and intermittently - never fan or ride them.

Railroad crossing rule: stop within 15 to 50 feet of the nearest rail when carrying placarded hazmat, passengers, or when a stop is posted; never stop on the tracks.

Alcohol limits: 0.04% BAC for holders of a CDL, 0.02% for drivers under 21, and 0.08% for other drivers; refusal to test triggers a one-year CDL disqualification.

Air pressure must build from 85 to 100 psi within 45 seconds at fast idle; the low-pressure warning must activate before pressure drops below 60 psi.

Governor cut-out is typically 120–140 psi and cut-in about 20–25 psi lower; if pressure never reaches cut-out, the compressor or governor is faulty.

Static leakage limits: 3 psi per minute for a single vehicle and 4 psi per minute for a combination, tested with the engine off and the system fully charged.

Applied leakage limit: with the service brake fully applied and held, loss must not exceed 4 psi per minute; release the brake before rechecking.

The spring (parking) brake applies automatically when pressure falls to roughly 20–45 psi; this is why a slow leak can lock the wheels.

The safety valve on the air tank opens near 150 psi to protect the system; a valve that vents in normal operation indicates a faulty governor or compressor.

Brake lag is the time between pressing the pedal and the brakes applying at the wheels - about 0.4 second at 55 mph, adding roughly 32 feet to stopping distance.

A slack adjuster pushrod travel beyond the adjustment limit means the brakes are out of adjustment; the vehicle must be placed out of service.

Drain air tanks daily to remove moisture and oil; the supply tank is drained first, and the drain cocks are closed before driving.

Tractor protection valve: the trailer air supply (red) knob controls air to the trailer and closes automatically if a trailer breaks away; the trailer hand valve (johnson bar) is for testing only, never for parking or normal stopping.

Tug test: after coupling, pull gently against the locked trailer brakes and check that the trailer does not move, then release and verify the fifth-wheel jaws are closed around the kingpin.

Fifth-wheel inspection: check the mounting bolts, that the jaws are locked, the release lever is secured, and the locking pin is in place; a gap between the apron and the fifth wheel is a defect.

Trailer air lines: the emergency (supply) line is red and the service line is blue; crossed or reversed lines cause the trailer brakes to stay applied or fail to release.

Off-tracking: the rear wheels of a combination follow a shorter path than the front; at a 90-degree turn the rear of a 55-foot trailer can swing out up to 5 feet beyond the path of the tractor.

Swing-out rule: the rear of the trailer swings wide in the opposite direction of the turn, so check both mirrors and the outside corner before turning.

Brake test for a combination: with the trailer brakes released and the tractor brakes applied, the combination must not move; then test the trailer brakes alone.

Rollover risk rises with a high center of gravity; posted curve speeds are for cars, so a loaded combination should enter curves well below the posted speed.

Coupling order: secure the trailer, back under slowly, listen for the click, tug test, connect air lines and electrical cord, then raise the landing gear.

Placards are required for 1,001 lb or more aggregate gross weight of a hazard class in one vehicle, and any quantity of Table 2 materials; the placard matches the hazard class, not the individual material.

The shipping paper must describe the hazard in order: proper shipping name, hazard class or division, UN/NA identification number, and packing group (e.g., Gasoline, 3, UN1203, PG II).

The emergency response information must accompany the shipping paper, and the shipping paper must be kept within reach of the driver, in a pocket or holder near the door.

A hazardous materials endorsement requires a TSA security threat assessment; the endorsement is valid for the same period as the license and must be renewed with a new assessment.

Parking rules: never park within 5 feet of a roadway, and stay at least 300 feet from open flames, bridges, tunnels, and heavily populated areas unless the shipper directs otherwise.

The ERG guide number and the four-digit UN number are used by responders; the driver should know the material's class, the placard, and the emergency phone number on the shipping paper.

Cargo securement for hazmat: packages must be blocked and braced to prevent movement, and leaking packages must not be loaded or transported.

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

A placarded vehicle must stop before every railroad crossing, and the driver must look and listen before proceeding; never stop on the tracks.

Class A = combination vehicle with GCWR of 26,001 lb or more, towed unit over 10,000 lb; Class B = single vehicle 26,001 lb or more, or towing 10,000 lb or less; Class C = 26,000 lb or less carrying 16+ passengers or placarded hazmat.

Pre-trip inspection order: engine compartment (fluids, belts, hoses, steering, exhaust, leaks) → walk-around lights and tires → brake test (air buildup, leakage, service and parking brake).

Air brake check sequence: build to governor cut-out, key off, verify no more than 3 psi loss in one minute (single vehicle) and no more than 4 psi (combination); then apply service brake and hold 5 minutes.

Following distance at speeds under 40 mph: one second per 10 feet of vehicle length plus one extra second; a 60-foot vehicle at 40 mph needs 7 seconds.

Stopping distance = perception distance + reaction distance + brake lag distance + braking distance; total stopping distance at 55 mph for a loaded rig is roughly the length of a football field.

Speed and space rules: reduce speed by at least 1/3 on wet roads, by half on packed snow, and crawl on ice; never drive faster than conditions allow regardless of the posted limit.

Downgrade rule: select a gear low enough that engine braking holds the speed without using the brakes, and use the brakes only lightly and intermittently - never fan or ride them.

Railroad crossing rule: stop within 15 to 50 feet of the nearest rail when carrying placarded hazmat, passengers, or when a stop is posted; never stop on the tracks.

Alcohol limits: 0.04% BAC for holders of a CDL, 0.02% for drivers under 21, and 0.08% for other drivers; refusal to test triggers a one-year CDL disqualification.

Air pressure must build from 85 to 100 psi within 45 seconds at fast idle; the low-pressure warning must activate before pressure drops below 60 psi.

Governor cut-out is typically 120–140 psi and cut-in about 20–25 psi lower; if pressure never reaches cut-out, the compressor or governor is faulty.

Static leakage limits: 3 psi per minute for a single vehicle and 4 psi per minute for a combination, tested with the engine off and the system fully charged.

Applied leakage limit: with the service brake fully applied and held, loss must not exceed 4 psi per minute; release the brake before rechecking.

The spring (parking) brake applies automatically when pressure falls to roughly 20–45 psi; this is why a slow leak can lock the wheels.

The safety valve on the air tank opens near 150 psi to protect the system; a valve that vents in normal operation indicates a faulty governor or compressor.

Brake lag is the time between pressing the pedal and the brakes applying at the wheels - about 0.4 second at 55 mph, adding roughly 32 feet to stopping distance.

A slack adjuster pushrod travel beyond the adjustment limit means the brakes are out of adjustment; the vehicle must be placed out of service.

Drain air tanks daily to remove moisture and oil; the supply tank is drained first, and the drain cocks are closed before driving.

Tractor protection valve: the trailer air supply (red) knob controls air to the trailer and closes automatically if a trailer breaks away; the trailer hand valve (johnson bar) is for testing only, never for parking or normal stopping.

Tug test: after coupling, pull gently against the locked trailer brakes and check that the trailer does not move, then release and verify the fifth-wheel jaws are closed around the kingpin.

Fifth-wheel inspection: check the mounting bolts, that the jaws are locked, the release lever is secured, and the locking pin is in place; a gap between the apron and the fifth wheel is a defect.

Trailer air lines: the emergency (supply) line is red and the service line is blue; crossed or reversed lines cause the trailer brakes to stay applied or fail to release.

Off-tracking: the rear wheels of a combination follow a shorter path than the front; at a 90-degree turn the rear of a 55-foot trailer can swing out up to 5 feet beyond the path of the tractor.

Swing-out rule: the rear of the trailer swings wide in the opposite direction of the turn, so check both mirrors and the outside corner before turning.

Brake test for a combination: with the trailer brakes released and the tractor brakes applied, the combination must not move; then test the trailer brakes alone.

Rollover risk rises with a high center of gravity; posted curve speeds are for cars, so a loaded combination should enter curves well below the posted speed.

Coupling order: secure the trailer, back under slowly, listen for the click, tug test, connect air lines and electrical cord, then raise the landing gear.

Placards are required for 1,001 lb or more aggregate gross weight of a hazard class in one vehicle, and any quantity of Table 2 materials; the placard matches the hazard class, not the individual material.

The shipping paper must describe the hazard in order: proper shipping name, hazard class or division, UN/NA identification number, and packing group (e.g., Gasoline, 3, UN1203, PG II).

The emergency response information must accompany the shipping paper, and the shipping paper must be kept within reach of the driver, in a pocket or holder near the door.

A hazardous materials endorsement requires a TSA security threat assessment; the endorsement is valid for the same period as the license and must be renewed with a new assessment.

Parking rules: never park within 5 feet of a roadway, and stay at least 300 feet from open flames, bridges, tunnels, and heavily populated areas unless the shipper directs otherwise.

The ERG guide number and the four-digit UN number are used by responders; the driver should know the material's class, the placard, and the emergency phone number on the shipping paper.

Cargo securement for hazmat: packages must be blocked and braced to prevent movement, and leaking packages must not be loaded or transported.

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

A placarded vehicle must stop before every railroad crossing, and the driver must look and listen before proceeding; never stop on the tracks.