CDL General Knowledge Test flashcards

The amount of movement in the steering wheel before the steering mechanism begins to turn the wheels.

• Excessive play indicates worn components.
• Maximum allowable is 10 degrees or ~2 inches on a 20-inch wheel.
• Checked during pre-trip inspection.

Memory trick: Ten degrees or three inches, no more for a good drive.

A properly coupled fifth wheel ensures the kingpin is fully engaged in the locking jaws with the safety latch secured, preventing trailer separation.

• Kingpin fully seated.
• Locking jaws closed.
• Safety latch engaged.

Memory trick: Kingpin locked, safety latched, trailer attached.

The visual check to ensure the fifth wheel's locking jaws are properly closed around the trailer's kingpin shank, confirming a secure mechanical connection.

• Performed immediately after backing under the trailer.
• Precedes the tug test and raising landing gear.
• Critical for preventing accidental uncoupling.

Memory trick: Back, Look, Tug, Connect, Lift, Inspect.

The sum of working load limits of all tie-downs must equal at least half of the total cargo weight.

• WLL must be 50% or more of cargo weight.
• Applies to the entire load or individual articles, depending on securement.
• Essential for preventing cargo movement.

Memory trick: Sum the weights, halve the sum, that's the WLL to overcome.

Methods to assess cargo securement and balance in a sealed trailer without opening it.

• Visual cues are primary for sealed trailers.
• Look for uneven suspension or leaning.
• Listen for unusual sounds during movement.

Memory trick: Look, listen, feel — don't break the seal.

The forward and backward motion of liquid in a partially filled tank caused by inertia during acceleration and deceleration.

• Most dangerous in partially filled tanks.
• Causes sudden shifts in vehicle's center of gravity.
• Requires careful braking and acceleration.

Memory trick: Sloshing liquid, shifting weight, makes driving tricky.

The sum of the working load limits of all tie-downs used to secure an article of cargo, which must be at least 50% of the cargo's weight.

• WLL is typically stamped on tie-down devices.
• Must be calculated for all tie-downs in use.
• Failure to meet WLL requirement is a serious safety violation.

Memory trick: Half the weight, total WLL must rate.

Cargo securement method where devices are attached directly to the cargo and to the vehicle to prevent movement.

• Physically restricts cargo movement.
• Examples: tie-downs, chains, bolts.
• Often used in conjunction with other methods.

Memory trick: Direct means attached, indirect relies on friction.

Federal Motor Carrier Safety Regulations (FMCSR) dictate the minimum number and strength of tie-downs required for cargo.

• At least one tie-down for every 10 feet of cargo.
• Minimum of two tie-downs for any article not fully contained.
• Tie-downs must be properly tensioned and free from damage.

Memory trick: Length + Minimum = Secure Load.

Methods for drivers to monitor general freight in enclosed trailers, especially when direct access is limited.

• Driver responsible for safe transport regardless of seal.
• Indirect checks (vehicle stance, sounds) are crucial.
• Cargo can shift even in enclosed trailers.

Memory trick: Sealed or not, your eyes and ears are your cargo spot.

Specialized methods for securing heavy, cylindrical steel coils to prevent rolling and shifting.

• High risk of rolling/shifting.
• Chocks and cradles are essential.
• Tie-downs must be properly positioned and tensioned.

Memory trick: Round and heavy, cradles hold steady.

Ensuring the weight of the cargo is evenly distributed and within the vehicle's limits to maintain stability and prevent hazards.

• Improper balance can lead to rollovers.
• Overloading can damage suspension and tires.
• Weight must be within Gross Vehicle Weight Rating (GVWR).

Memory trick: Balance keeps the big rig on track, preventing a crash.

Visual indicators required for loads extending beyond the vehicle's rear during daylight hours to alert other drivers.

• Required for overhangs 4 feet or more.
• Must be a red flag, at least 12 inches square.
• Placed at the extreme end of the load.

Memory trick: Daylight needs a flag, night needs a light.

Special considerations for transporting live animals, focusing on their welfare and humane treatment.

• Ventilation is key to prevent heat stress.
• Avoid overcrowding to prevent injury.
• Regular checks are needed for animal well-being.

Memory trick: Happy cows need air and space, not a fancy meal.

Special considerations for refrigerated cargo where items are suspended, leading to unique stability challenges.

• High center of gravity.
• Risk of swinging during maneuvers.
• Increased rollover potential.

Memory trick: Hanging high, it sways and tips, watch your speed on curves and dips.

Any component of the cargo securement system that is broken, frayed, or otherwise compromised, requiring immediate attention.

• Compromises safety of load and other road users.
• Requires immediate action to repair or replace.
• Failure to address can lead to fines and accidents.

Memory trick: Secure load, safe road; damaged means stop and mend.

Specific federal regulations govern the securement of vehicles (cars, trucks, etc.) transported as cargo on a commercial motor vehicle.

• Minimum of four tiedowns per vehicle.
• Tiedowns prevent movement in all directions.
• Tiedowns must be attached to the vehicle frame or axles.
• Parking brake must be set.

Memory trick: Four points on the frame, no wiggle, no blame!

Federal regulations specify minimum tiedown requirements based on cargo length and weight to prevent movement.

• Minimum of 2 tiedowns for any article.
• One tiedown for every 10 feet of cargo length, or fraction thereof.
• For articles 10 feet or longer AND weighing 10,000 lbs or more, a minimum of 4 tiedowns are required.

Memory trick: Length first, then weight, don't forget the big four for heavy freight!

The circulation of cold air within a refrigerated trailer to maintain consistent temperatures for perishable cargo.

• Requires space around and between cargo.
• Blocked airflow creates 'hot spots'.
• Essential for cargo preservation.

Memory trick: Air needs to flow, for the cold to grow, or your cargo will spoil, you know!

Specific FMCSA regulations govern the securement of baled hay and similar agricultural products, especially when stacked.

• Top tier of bales requires at least two tiedowns.
• Tiedowns must prevent movement in all directions.
• Side structures can reduce tiedown requirements if fully contained.
• Weight distribution is also critical.

Memory trick: Hay stack high, two straps on the top, or watch it fly!

A protective barrier at the front of a flatbed trailer, behind the cab, to prevent cargo from shifting forward.

• Protects driver and cab.
• Essential safety feature for flatbeds.
• Prevents injury from sudden stops.

Memory trick: A headache rack for a shifting attack, keeps the driver safe in the back.

The total Working Load Limit (WLL) of all tiedowns used to secure a piece of cargo must be at least half the weight of the cargo itself.

• WLL is the maximum weight a tiedown can safely handle.
• Aggregate WLL is the sum of the WLLs of all tiedowns.
• Formula: Aggregate WLL ≥ 0.50 * Cargo Weight.
• Ensures adequate strength to prevent cargo movement.

Memory trick: Half the weight, or it's not alright!

Specific FMCSA rules dictate the minimum number of tiedowns for logs not contained in bunks, based on log length.

• Logs 10 feet or less: 2 tiedowns.
• Logs 10 to 20 feet: 2 tiedowns.
• Logs over 20 feet: 3 tiedowns.
• Tiedowns must be placed to prevent rolling and shifting.

Memory trick: Short logs get two, long logs need three, keep them from rolling, wild and free!

For cargo not blocked or braced against movement, there must be at least one tie-down for every 5 feet of cargo length.

• Applies to flatbed loads without blocking.
• Ensures adequate securement against shifting.
• Minimum of two tie-downs always required.

Memory trick: Tie down your load, count every five feet, or risk a fine and a bad street.

Federal regulations specify minimum tiedown requirements for dressed lumber based on its length, particularly for longer stacks.

• Stacks 10 ft or longer: 3 tiedowns.
• Stacks 20 ft or longer: 4 tiedowns.
• Stacks 30 ft or longer: 5 tiedowns.
• Stacks 40 ft or longer: 6 tiedowns.

Memory trick: Longer the lumber, more straps you need, 40 feet means six, indeed!

The practice of spreading cargo weight uniformly over a vehicle's axles and tires.

• Prevents axle overloading.
• Improves vehicle handling and stability.
• Reduces wear on components.

Memory trick: Balance is key, for truck and for me, to avoid wear and drive free.

Heavy cylindrical articles (pipes, rolls) not secured in cradles or bunks require specific tiedown configurations to prevent rolling and longitudinal movement.

• Minimum of 2 tiedowns to prevent rolling.
• Additional 2 tiedowns to prevent forward/backward movement (total 4).
• Tiedowns must be placed to provide maximum securement.
• Applies to items over 1,100 lbs and large diameter.

Memory trick: Heavy pipe, no cradle, four straps to keep it stable!

Bunks or cradles are structural components used in log transport to physically contain logs and provide lateral stability.

• Prevent logs from rolling or shifting sideways.
• Reduce the number of tiedowns required compared to unbunked logs.
• Must be strong enough to withstand forces.
• Are a form of 'blocking' for cylindrical cargo.

Memory trick: Bunks cradle the logs, stops them from rolling like dogs!

Methods to prevent rolling and longitudinal movement of items like pipes, coils, or drums.

• Requires blocking, chocks, or cradles.
• Tie-downs must provide vertical and/or diagonal restraint.
• End blocking is crucial for longitudinal securement.

Memory trick: Rollers need blocking, chains need tension, keep them from moving in any dimension.

A cargo securement technique using physical barriers placed along the sides of cargo to prevent lateral (side-to-side) movement.

• Prevents cargo from sliding left or right.
• Critical for turns and uneven road surfaces.
• Often used in conjunction with tiedowns.
• Must be strong enough to withstand forces.

Memory trick: Side blocks are for the slide, keeping cargo from taking a ride!

Partial loads of loose, bulk materials (like sand, gravel, grain) are prone to shifting significantly during vehicle maneuvers, creating instability.

• Can cause loss of steering or braking control.
• Requires careful loading and potentially specialized equipment.
• More dangerous than a full, settled load.

Memory trick: Loose sand on a truck, a sudden brake, and the truck will buck!

Documents that describe the hazardous materials being transported, including hazard class, ID number, and emergency response information.

• Must be kept within reach of the driver.
• Essential for emergency responders.
• Also known as a manifest.

Memory trick: Hazmat papers in plain sight, for safety day and night.

Metal coils transported with their eyes (center holes) facing sideways require specific securement methods to prevent rolling and shifting.

• Must be placed in a cradle, rack, or adequately blocked/braced.
• At least one tiedown per coil.
• Tiedown must pass through the eye or secure against shifting.

Memory trick: Side-eye coil, prevent the roll, one strap to make it whole!

Cargo stacked in multiple tiers, where items are not interlocked or contained by vehicle structure, requires specific securement for each tier.

• Each tier must be secured.
• Upper tiers typically require at least two tiedowns.
• Tiedowns prevent movement in all directions (vertical, horizontal).
• Blocking may be used in conjunction with tiedowns.

Memory trick: Stacked high, not intertwined, two straps for the top, keep it aligned!

Irregularly shaped, heavy cargo (e.g., boulders, machinery) requires securement methods that specifically address their unpredictable movement patterns.

• Prone to rolling, tipping, and shifting.
• Blocking, bracing, and cradles are essential.
• Tiedowns work in conjunction with blocking to secure.
• Focus on preventing any movement in any direction.

Memory trick: Boulders rock, but don't let them roll, block and brace to take control!

Different tiedown configurations are more effective for specific types of cargo movement, especially for cargo prone to rolling.

• Overhead tiedowns apply downward force.
• Downward force increases friction, preventing rolling.
• Direct tiedowns primarily prevent sliding.
• Blocking/chocks are also crucial for rolling prevention.

Memory trick: To stop the roll, put a strap over the whole!

The protocol for commercial vehicles when encountering railroad tracks that appear unused or unmaintained, requiring them to be treated as active and dangerous.

• All tracks must be treated as active.
• Requires a full stop before crossing.
• Look and listen in both directions before proceeding.

Memory trick: Abandoned tracks, still a threat, stop, look, listen, no regret!

The increased space a driver maintains behind another vehicle when conditions like rain, snow, or fog reduce visibility or traction.

• Wet roads double stopping distance.
• Reduced visibility decreases reaction time.
• More space allows for safer braking and maneuvering.

Memory trick: Rain, Snow, Fog? Give More Space, No Hog!

Procedures to ensure a commercial vehicle remains stationary when parked on an incline or decline, preventing accidental rolling.

• Parking brake is primary.
• Wheel chocks are secondary, crucial backup.
• Gear selection adds resistance.
• Steering wheel position can guide vehicle if it rolls.

Memory trick: Park on a hill? Chock it, chill!

A condition in hydraulic brake systems where the brake pedal feels soft or 'mushy' when pressed, often indicating the presence of air or moisture within the brake lines.

• Caused by compressible substances (air/moisture) in lines.
• Reduces braking effectiveness.
• Requires bleeding the brake system to remove contaminants.

Memory trick: Spongy pedal, air in the lines, time for a bleed, no more whining!

A systematic process for changing lanes safely in a commercial vehicle, minimizing the risk of collisions.

• Check mirrors for traffic.
• Signal your intention.
• Perform a head check for blind spots.
• If clear, execute the lane change smoothly.

Memory trick: Mirrors, signal, head check, then you direct.

Pre-trip checks and procedures specifically aimed at preventing brake failure when driving heavy vehicles on long, steep downgrades.

• Inspect and adjust all service brakes (slack adjusters).
• Ensure air pressure system is working correctly (for air brakes).
• Test parking brake and emergency brake systems.
• Choose the correct low gear before starting descent.

Memory trick: Before you descend, check your brake's friend.

Measures taken immediately after a vehicle accident to prevent further collisions and ensure the safety of those involved and oncoming traffic.

• Personal safety first.
• Warning devices are paramount.
• Prevents secondary accidents.
• Always report to authorities.

Memory trick: Safe, Warn, Call: Your accident response, that's all!

A defect where the seal designed to retain lubricant (oil or grease) within a wheel hub fails, causing leakage and risking severe damage to wheel bearings.

• Indicates compromised lubrication.
• Leads to wheel bearing overheating/failure.
• Can cause wheel separation.
• Requires immediate repair.

Memory trick: Oil leak? Seal's weak! Bearings at stake!

An emergency braking technique for vehicles without Anti-lock Braking Systems (ABS), where the brakes are applied firmly until just before lock-up, then released and reapplied.

• Apply brakes hard, then release when wheels are about to lock.
• Reapply brakes as soon as wheels roll again.
• Purpose is to maintain steering control by preventing full wheel lock-up.
• Different from ABS, which does this automatically.

Memory trick: Stab and release, steer with ease.

Using the vehicle's engine and transmission to slow down by selecting a lower gear, thereby reducing the reliance on and potential overheating of the service brakes, especially on long, steep descents.

• Crucial for mountainous driving.
• Prevents brake fade/failure.
• Lower gear = higher engine RPM.
• Should be done BEFORE starting the grade.

Memory trick: Downshift early, save your brakes, no worries!

An indicator light on the dashboard that illuminates when there is a problem with the vehicle's charging system, specifically the alternator.

• Indicates the alternator is not producing sufficient electrical power.
• Can lead to battery discharge and vehicle failure.
• Requires immediate attention from a mechanic.

Memory trick: Alternator light: your power's not right.

The speed at which the air compressor can increase air pressure in the air tanks from a specified low pressure to a specified high pressure.

• Single vehicle: 85 to 100 psi in 45 seconds or less.
• Combination vehicle: 85 to 100 psi in 45 seconds or less.
• Ensures the compressor is capable of maintaining adequate air supply.

Memory trick: Pressure builds, safety ensures.

The immediate actions taken by a commercial driver after a minor accident to ensure safety and prevent further incidents.

• Prioritize human safety first.
• Move vehicle if drivable and safe.
• Prevent secondary collisions.

Memory trick: Safety first, move it fast, then report the past.

Strategies and immediate actions to prevent and mitigate the dangers of drowsiness while operating a commercial vehicle.

• Fatigue impairs judgment and reaction time
• Rest is the only cure
• Temporary fixes are dangerous

Memory trick: Rest is Best for a Drowsy Driver's Test.

Large commercial vehicles have significant blind spots, often called 'No-Zones,' where smaller vehicles disappear from a driver's view. These areas are directly in front, behind, and on either side of the truck.

• Front blind spot: up to 20 feet.
• Rear blind spot: up to 200 feet.
• Side blind spots: extend from the cab to beyond the rear of the trailer, especially on the right side.
• Always check mirrors and use turn signals well in advance.

Memory trick: No-Zones are real, check all you can feel, before you steer!

The legally mandated distance at which a driver must switch from high beams to low beams when approaching an oncoming vehicle to prevent glare and maintain visibility for other drivers.

• Required at approximately 500 feet for oncoming vehicles.
• Prevents temporary blindness (glare) for other drivers.
• A crucial aspect of safe night driving.

Memory trick: Five hundred feet, dim your brights, make the night safe and right!

A condition in air brake systems where the pushrod extends beyond its safe limit when the brakes are applied, indicating improper slack adjuster adjustment or failure, compromising braking effectiveness.

• Indicates slack adjuster issue.
• Reduces braking force.
• Increases stopping distance.
• A major safety defect requiring repair.

Memory trick: Pushrod long? Slack adjuster's wrong!

A significantly slower-than-normal air pressure build-up rate in a commercial vehicle's air brake system during a pre-trip inspection.

• Indicates a potential leak in the air brake system.
• Compressor works harder to maintain pressure.
• Can lead to insufficient braking power.

Memory trick: Slow air build-up means a sneaky escape.

The proper technique for positioning a commercial motor vehicle before executing a left turn at an intersection to prevent cutting the corner.

• Approach in the left-most lane.
• Keep to the right side of that lane.
• Allows for a wider turning radius.

Memory trick: Left turn, right approach, smooth arc.

Commercial vehicle drivers must exercise extreme caution at railroad crossings. Never stop on the tracks, and always ensure sufficient space to clear the tracks on the other side before proceeding.

• Always look and listen for trains.
• Never shift gears while on tracks.
• Ensure enough room to clear the tracks completely.
• Be aware of 'Do Not Stop On Tracks' signs.

Memory trick: Look, listen, and clear the tracks, or you'll have no way backs!

The most common cause of overheating in dual tires is under-inflation of one or both tires. This leads to uneven load distribution and excessive flexing, generating heat.

• Under-inflated tires flex more, generating heat.
• In duals, one under-inflated tire overloads the other.
• Proper inflation is crucial for tire longevity and safety.
• Check tire pressure regularly, especially before trips.

Memory trick: Duals too hot? Pressure's forgot!

The sequence of actions a commercial driver should take immediately following an accident to ensure safety, comply with regulations, and manage the scene.

• Safety first
• Clear obstruction if possible
• Document and report

Memory trick: Safety, Clear, Report, Record.

A test performed on an air brake system to check for leaks by applying the foot brake and observing the pressure drop over a specified time.

• Engine off, parking brake off, foot brake applied.
• After initial drop, pressure should not drop more than 3 psi in one minute for a single vehicle.
• For combination vehicles, not more than 4 psi in one minute.
• Excessive loss indicates dangerous leaks.

Memory trick: Foot down, pressure drops, over 3 psi, trouble crops.

The practice of frequently checking tire pressure and condition when operating a commercial vehicle in high temperatures to prevent overheating, overinflation, and blowouts.

• Heat causes air in tires to expand, increasing pressure.
• Overinflated or damaged tires are more prone to blowouts.
• Regular checks are essential for safety and tire longevity.

Memory trick: Sun's a blaze, check your tires, avoid those fiery snares!