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376 Cards in this Set

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Located under the steering wheel, you can operate this pedal with you right foot to control engine speed.
Spanish word
Access Panels
Panels granting access to controls, vehicle parts and storage for tools and other items.
The Federal Highway Administrator, chief executive of the Federal Highway Administration with DOT.
Aerodynamic buffeting
As you drive your double or triple rig down the highway, you are cutting through the wind and as you cut through a draft is created behind you.
Air brakes
These brakes use air instead of fluid to stop or break. They require special handling and an additional permit on your CDL.
Blood alcohol level
Commerical Vehicle Safety Act of 1986- requires all 50 states to meet the same minimum standards in testing and licensing of all commerical drivers and requires that all commerical motor vehicle drivers must pass to obtain the CDL.
A vehicle carrying two trailers or tankers.
An authorization to an indicidual's CDL that is required to permit the individual to operate certain types of commerical motor vehicles.
Hazardous Materials
A group of materials that the Secretary of Transportation judges to pose a threat or risk to safety, health, or property while it is being transported in commerce; the meaning such term has under section 103 of the Hazardous Materials Transportation Act.
Knowledge test
Written tests that a driver must pass in order to receive a CDL or special permits.
A sign placed on cargo to indicate the the shipment contains hazardous materials. These signs must be visible from all angles.
Pre-trip inspection
Before you begin to drive, a check of your vehicle to make sure that all systems are damage free and working properly to ensure safe driving.
Stopping and remaneuvering to the correct position.
Skills test
The Acutla driving test to make sure that a driver can operate a trailer or tanker.
Special trailer used to carry liquids or dry bulk loads, such as grains, chemicals, etc.
A vehicle carrying three trailers or tankers.
The Federal Highway Administrator, the chief executive of the Fedreal Highway Administrator, and agency with in the Department of Transportation.
Alcohol or "alcoholic beverage"
Beer, wine, distilled spirits, or liquor.
Alcohol concentration (AC)
The concentration of alcohol in a person's blood or breth. When expressed as a percentage, it means grams of alcohol per 100 milliliters of blood or per 210 liters of breath.
Any trade, traffic, or transportation with in the jurisdiction of the United States between a place in a state and a place outside of that state, trade, traffic, and transportation in the United States, which affects any trade, traffic and transportation.
Commerical Driver's License (CDL)
A license issued by a state or other jurisdiction to an individual, which authorizes the individual to operate a specified class of ommericial motor vehicle.
Commerical driver's license information system (CDLIS)
Established by FHWA pursuant to section 12007 of the Commercial Motor Vehicle Safety Act of 1986.
Commerical motor vehicle (CMV)
A motor Vehicle or combination of motor vehicles used in commerce to transport passengers or property if the vehicle has a gross combination weight rating of 11,794 kilograms or more (26,001 pounds or more) inclusive of a towed unit with a gross vehicle weight rating of more than 4536 kilograms (10,000 pounds); or is designed to transport 15 or more passengers, including the driver.
Controlled substance
Includes all substance listed on the schedules I-V of 21 CFR1308 (Secs. 1308.11 through 1308.15)
A determinatin that a person has violated or failed to comply withthe law in a court of original jurisdiction or a violation of a condition of release without bail, regardless of whether the penalty is rebated, suspended, or probated.
The suspension, revocation, cancelation, or any other withdrawal by a state of a person's privilege to drive or a determination by the FHWA, under the rules of practice for motor carrier safety-taht person is no longer qualified to poerate a commercial motor vehicle.
Driver applicant
An individula who applies to a state to obtain, transfew, upgrade, or renew a CDL.
Driver's license
A license issued by a state or other jurisdiction to an individula which authorizes the individula to operatea motor vehicle on the highways.
Driving a commercial motor echicle while under the influence of alcohol
Driving a CMV with a blood alcohol concentration of 0.04% or more; driving under the influence of alcohol, as prescribed by state law; or refusal to undergo such testing.
Any Operator of a commercial motor vehicle, including full-time, regularly employed drivers; casual, intermittent, or occasional driver; leased drivers; and independent, owner-operator contractors.
Any person or entity (including the United States, a state, the District of Columbia, or a political subdivision of a state)who owns or leases a commercial motor vehicle or assigns employees to operate such a vehicle.
Optional tests that allow drivers to add permits for certain vehicles or cargo.
An offense under state or federal law that is punishable by death or by imprisonment for a term exceeding one year.
Outside the 50 United States and the Distric of Coulmbia
Gross combination weight rating (GCWR)
The value specified by the manufacturer as the loaded weight of a combination vehicle. In the absence of a value specified by the manufacturer, GCWR will be determined by adding the GCWR of the power unit and the total weight of the towed unit and any load thereon.
Gross vehicle weight rating
The value specified by the manufacturer as the loaded weight of a single vehicle.
Hazardous materials (HazMat)
A group of materials that the Secretary of Transportation judges to pose a threat or risk to safety, health, or property while it is being transported in commerce; the meaning such trem has under section 103 of the Hazardous Materials Transportation Act.
Motor vehicle
A vehicle, machine, tractor, trailer, or semi-trailer propelled or drawn by mechanical power, used onhighways, execpt that such term does not include a vehicle, machine, tractor, trailer, or semi-trailer operated exclusively on a rail.
Nonresident CDL
A CDL issued by a state to an individual living in a foreign country.
Out of service order
A declaration by an authroized enforcement officer of a federal, state, Canadian, Mexican, or local jurisdiction that a driver, commercial motor vehicle, or motor carrier operation may not continue to operate.
Representative vehicle
A motor vehicle which represents the type of vehicle that a driver applicant operates or expects to operate.
Serious traffic violation
A conviction received when operating a commericail motor vehicle for excessive speeding, reckless driving, improper or erratic traffic lane changes, following the vehicle ahead too closely, or a violation arising in connection with a fatal accident.
A state of the United States and the District of Columbia.
State of domicile (or residence)
The state where a person has his or her true, fixed, and permanent home and the principal residence to which he or she has the intention of returning whenever he or she is absent.
Tank vehicle
Any commercial vehicle that is designed to transport any liquid or gaseous materials within a tank that is either permanently or temporarily attached to the vehicle or the chassis.
United States
The term United States means the 50 states and the District of Columbia.
A motor vehicle, unless otherwise specified. Also, any wheeled contraption including motorcycles, automobiles, trucks, and tractor-trailer rigs.
Vehicle group
A class or type of vehicle with certain operating characteristics.
Air backflow
If the tractor air supply develops a problem, air from the trailer air supply would have a tendency to "back flow" and fill the tractor's air supply. If this happens, both tractor and trailer would be left powerless.
Air pressure
Compacting air and storing it in a small space. Compressing it creates energy and this energy operates the air brakes.
Bobtail tractor
The lead tractor and power supply when towing trailers or other tractors.
Brake reservoirs
For air or vacuum braking systems, the reservoirs (or tanks) store the compressed air until it is needed.
Braking Distance
The perception time plus the reaction time plus the brake lag-needed to stop a rig. Usually calculated to include speed.
Braking force
A percentage of the GVWR or the GCWR.
Braking Performance
A combination of how quickly the brakes stop the vehicle and how far the vehicle travels before it stops. Braking performance is also measured by how much force must be applied to the brakes before the vehicle stops.
Braking rate
The ability of a vehicle's brakes to stop the vehicle when traveling at a certain speed; these specifications are provided for the manufacturer and the vehicle must at least meet the required braking rate.
Cargo securement
Making sure the cargo does not shift or fall.
Clearance lights
Lamps that outline the length and width of the vehicle. These lights are found at the widest part of the sides, back, and the front of the vehicle.
Slowing the vehicle.
Defrosting device
An element associated with the vehicle's heathing unit that clears the windshield of any ice or foggy distraction.
A method of hauling in which the cargo is one or more vehicles with one or more sets of wheels on the roadway.
Emergency brakes
Stops the vehicle in an emergency situation-usually caused by failure of the braking system.
Field of vision
The area in which you can see in front of you.
Fluid pressure
The nature of fluids is to flow; when they cannot, pressure is created- fluid pressure is used to operate hydraulic brakes.
Fuel system
Provides energy to the engine so that it will run.
Groove Pattern
The area between the tread ribs.
Protects the driver from teh freight shifting or cruching him or herin an accident or a suddent stop.
Warms the cab of the vehicle.
Hydraulic braking system
Brakes that use fluid pressure to stop.
Intermodal containers (fishyback/piggyback)
Containers sealed by the shipper, transported by boat, and then loaded on trailers for final delivery. Shippers prefer containers because they resist pilferage (theft) and other problems.
Noise levels
The concentration of noise.
Parking brakes
Brakes used when you park the vehicle.
Detachable connections-electrical connections between towing and towed vehicles-made by simply twisting wires together with shielded cables.
Pole trailers/pulpwood trailers
A trailer that is composed of a telescopic pole, a tandem rear wheel unit, and a coupling device used to join the trailer to a tractor.
Projecting loads
Cargo that has projecting items which need flags to warn others of the protruding objects. The load much extend more than four inches from the sides of the truck or four feet beyond the rear of the truck. Flags used to mark porjecting loads must be at least 12 inches square and must be red.
Pounds per square inch (psi)
Pounds per square inch.
Rear-end projection
Projection four feet beyond the rear of the truck. Flags used to mark projecting loads much be at least 12 inches square and must be red.
Service brakes
The vehicle's main braking system-used to stop the vehicle in regular driving situations.
Spring brakes
Also known as fail-safe brakes. The most commonly used emergency brake and/or parking brake system on tractors and buses. They must be mechanical because air can leak off. Otherwise, they are the conventional brake chambers.
Steering wheel lash
Usually caused by hitting an object or hole-causes the steering wheel to lash back in the opposite direction. To prevent injury, keep thumbs outside the steering wheel when wrapping your hands around it.
Television receiver
Device that receives television signals. FMCSR states that a television set must be installed behind the driver's seat or otherwise outside of the driver's line of vision while he or she is driving. The regulation further states that the television set must be placed in such a manner that the driver will have to leave the driver's seat to watch it.
A cagegory of chains, ropes, and other implements used to secure cargo.
Vacuum brakes
Type of brakes usually found on trailers, operated by knob control from the tractor and requiring air tanks to operate.
Driver's Record of Duty Status
A form submitted by the driver to the carrier after completing a 24-hour period of work.
Etiologic agents
Microorganisms (also known as germs) that can cause disease.
Hazardous Material(s).
Safe haven
A location approved for parking an unattened vehicle loaded with explosives.
Shipping papers
Documents that includ any information that is required by FMCRS Parts 172.202, 172.203 and 172.204.
Used to bind downs loads on flatbed trailers.
Braces and supports
Devices used to prevent the load from moving. Whether the vehicle is a flatbed or drybox, the load must be blocked or braced to prevent moving on all sides.
Used to stop the vehicle.
The part of the vehicle where the driver sits.
Cargo doors
Doors located at the back or side of trailer where cargo may be loaded or unloaded.
Cargo securement devices
Tie-downs, chains, tarps, and other methods os securing cargo in a flatbed.
Used for tiedown to secure cargo.
List the parts of the vehicle to check or inspect.
Coupling devices
A device-called a converter gear or dolly-that makes it possible to attach one trailer to another or to a tractor.
Dimmer switch
Located on the floor to the left of the brake pedal (if it isn't on the dashboard). This switch allows you to move the headlights from low beam to high beam.
Emergency equipment
Equipment needed during and emergency. For a commercial motor vehicle, the emergency equipment consists of a fire extinguisher, reflective emergency triangles, fuses (if needed), tire change kit, accident notification kit, and a list of emergency numbers.
Engine compartment
Area where the engine is located.
Exhaust system
Required on all motor vehicles and used to discharge gases created by the operation of the engine.
Used to mark over-length or over-wide vehicles.
Four-way flashers
Two amber lights located at the front and two amber lights or red lights located at the rear of the vehicle. These are usually the front and rear turn signals lights, equipped to do double duty as warning lights.
The metal infrastructure of any vehicle-creates the underpinnings to support the rest of the vehicle.
The white headlights, one to the right and one to the left, located on the front of the tractor-required on buses, trucks, and truck tractors. Used to illuminate the vehicle to help the driver see and to help others see the vehicle.
Used to communicate with other motorists.
Identification lights
Lights located on the top, sides, and back of a truck to indentify it as a large vehicle.
Inspection routine
List of steps you go through to inspect your vehicle-in the samw way each time-so that you don't forget a step.
Material used to maintain certain temperatures within trailers; particularly important in refrigerated units to maintain cool temperatures.
Help others to see you, help you to see others, to signal intentions (such as lane changes, slow down or stop), and communicate with other vehicles.
Rear bumper
The protective apparatus that prevents shorter vehicles from running under taller ones. Clearance between the bumper and the ground is no more than 30 inches, measured when the vehicle is empty.
Rear-view mirrors
Mirrors used to see on the sides and behind the vehicle.
Retarder controls
Controls that allow the engine to slow the speed of the vehicle, particularly on a downgrade.
Part of the vehicle that holds the tire in place.
Safety harness that holds the driver into the seat. Seatbelts should always be worn when driving-make sure and put it on before you start the vehicle.
Side marker lamps
Two amber lights located to each side or near the center of the vehicle between front rear side marker lamps. Required for buses, trucks, large semi-trailers, large full trailers, and pole trailers.
Splash guards (mud flaps)
Rubberized sheaths hanging behind the wheels that lessen amount of water or mud kicked up in back of a trailer or truck.
Spare tire
Additional tire used as a precaution in case something happens to the vehilc's tires.
Shows the vehicle's road speed in piles per hour (mph)
Steering system
The steering wheel, steering column, gearbox, Pitman arms, tie-rod ends, and front axle make up the entire steering system.
Springs used to support a vehilce and its axles.
Meterial used to cover most freight-tied down with rope, webbing, or elastic hooks.
Slang term for a vehicle following too closely.
Tire chains
Chain grids used on tires to provide additional traction on snowy or icy roadways.
Tire pressure
Amount of air pressure enabling tires to support their manimum weight.
Provide traction and reduce road vibration, transferring braking and driving force on the road.
Located between the drive shaft and the transmission and the drive shaft and the differential.
The process of putting the vehicle in reverse.
Black ice
A thin coating of ice that is usually invisible because you can see the roadway thought it.
Bleeding tar
Tar that bleeds to the driving surface and can be very slippery.
Blind spot
An area that you can't see with your rearview mirrors- usually from the rear axle to midway up the trailer and from midway down the door to the ground.
Process of using brakes.
Brake failure
Brakes do not work.
Bridge icing
In cold weather, bridges usually become icy before roads do. Drive slowly over bridges in cold weather.
Cancelling the turn signal
Shutting off the turn signal.
Clutch pedal
Located to the left of the brake, the clutch pedal is operated with the left foot. You press the clutch pedal to disengage the clutch, and release the pedal to engage the clutch.
Communicating with others
The use of lights, horns and hand signals to let other drivers know your intentions.
Liquid used to keep the engine cool.
Once you've steered around an obstacle in your path, you will turn the wheel back in the other direction.
An uneven highway where new pavement makes part of road higher than the rest, creating a "drop-off" that may be a driving hazard.
Escape ramp
A ramp-usually at the bottom of a down-grade-which drivers may use to stop their vehicle if the brakes fail.
Fish-eye mirror
Convex mirror, positioned on the side of the truck, usually providing driver with a wider view of the back of trailer; makes vehicle and objects appear smaller and farther away then they are.
Front wheel skids
The most common type of skid, resulting from over-braking or over-acceleration-can be stoped by taking foot off accelerator. If road conditions are slippery, push the clutch in.
Pertaining to the transmission. Each gear supplies a certain speed to the vehicle. The lower the gear, the slower the vehicle's speed and the greater pulling power.
The stick or lever located inside the tractor that the driver used to select the gear.
A condition caused by sun or bright lights reflection off pavement or a vehicle's glass or metal parts, causing difficulty in a driver's vision; particularly a problem when driving west as the sun is setting.
Harmful item or situation.
High beams
Lights used at night to see long distances. Use only when others cars are far away from you.
Occurs when water or slush collects on the roadway and the vehicle's tires ride on top of the water, instead of the roadway itself, causingthe driver to lose control of the vehicle.
Low beams
Normal headlight setting used to illuminate the vehicle to help the driver see and to hlep others see the vehicle.
Night driving
Driving at night.
On-ramp / Off-ramp
Ramps leading on and off the freeways. Some ramps may bank, so it is recommended that you enter and exit a ramp at speeds below the posted speed limit.
Turning the wheels more sharply than the vehicle can handle.
Perception distance
Distance the vehicle will travel from the time driver sees a hazard and the time the driver reacts (presses the break pedal).
Radiator shutters
Outter portion on the radiator; if the shutters freez shut, the engine may overheat and stop. Remove ice when this happenes.
Reaction distance
Time it takes for driver's foot to get off the accelerator and stomp on the brake.
Rear-wheel skids
Occurs when the rear drive wheels lock and have less traction, causing the rear of the vehicle to slide sideways. To correct, left off the brakes, allowing the rear wheels to roll again, and turn quickly. When the vehicle begins to slide sideways, quickly steer in the direction you want the vehicle to go.
Revolutions per minute. Read by a tachometer and indicates when to change gears.
Selector knob
An air-assisted lever on the gearshift which takes the transmission from low-range to high-range.
Shutting down the engine
Actually turning off the ignition and allowing the engine to cool.
Skid control
The ability to control the movement of the vehicle once it has entered a skid. Usually done by steering-never by braking.
Spotting mirror
Same as convex mirrors-objects appear smaller and farther away than they really are. Always check and adjust prior to each trip.
The acutal directing of the vehicle's movement-rolling frontward or backward.
Stopping distance
The time it takes for a vehicle to stop.
Instrument located on the dashboard indication the number of engine revolutions per minute (rpm). RPM is often used to indicate when to shift gears.
10 o'clock and 2 o'clock
If the steering wheel were a clock, those times would be where your hands would be placed.
Tire failure
When tires fail due to tire damage or defects.
Total stopping distance
Distance from the time you see the hazard until your rig has stopped-about the length of a football field. If you're traveling faster than 55 miles per hour, you're going to increase the distance it takes to stop. If you double your speed, it will take you four times the distance to stop.
The ability of your tires to "grab" the road.
Turn to the right
The most difficult maneuver because the driver can't see what is happening to the right of the vehicle.
Turning space
Turn wide at the begining of the maneuver or, if there is not enough room, turn wide as you complete the turn.
Visual awareness
A driver's constant checks of the right and left rear view mirrors and in front of vehicle to avoid obstacles, accidents, or situations that would endanger the driver and/or the load.
Warm up
Allowing the engine and fluids to heat up to normal running temperatures before starting the vehicle.
Going back and forth between lanes.
Work zones
Roads or highways that are under construction.
Air bag suspension
A trailer suspension system that used air bags instead of traditional springs.
Keeps the battery charged and powers the trucks systems while it is running.
The number of amperes generated by the vehicle's electrical system.
Backup lamp
One white lights located at the rear of buses, trucks, and truck tractors. It is a signal to other drivers that you are backing up.
Converts chemical energy to electricity. It is used to start the engine.
Belted bias ply
Tires on which the plies cross at an angle and there's an added layered belt of fabric between the plies and the tread. Belts make the ttead more riged than bias ply tires and the tread will last longer.
Brake pedal
Located just to the left of the accelerator and operated with your right foot. WHen you press down on the pedal, the brakes are applied and the vehicle shows down.
Closed circuit
An electrical circuit in a cpmpleted loop in which electricity's positive and negative poles are connected. This allows the current to travel from the source to its usage point.
Coil spring suspension
Dampens wheel vibration with coils that absorb "bounce" between the road and the tires.
Cold start and warm-up switch
Found on diesel engines. When the engine is cold, there's a start-up lag time. Turning the key allows the ejectors in the engine to warm up. A light comes on, letting you know the engine is warm enough to start.
Converter dolly
Used to connect the trailer to the tractor or to another trailer.
Control panel just beyond the steering wheel that houses all gauges, knobs, and other operating information so that the driver may operate the truck safely.
A tiny particle carrying a negative charge of electricity.
Engine temperature gauge
Usually marked "Temp" or "Water Temp." This guage indicated the temperature of the engine's cooling system in degrees.
Fifth wheel
Controls how much weight is distributed on each axle of the tractor. It is part of the locking device that is ued to connect a trailer and a tractor.
Fire extinguisher
Safety device used to put out fires.
Flammable cargo
Cargo that can ignite if exposed to a fire or flame.
Front clearance lamps
Two amber lamps located at each side of the front of large buses, trucks, trucks tractors, large semi-trailers, full trailers, pole trailers, and projecting loads.
Front identification lamps
Three amber lights located at teh center of the vehicle or cab. Required on large buses, and trucks, and trucks tractors.
Front side marker lamp
Two amber lights located to each side or near teh center of the vehicle between the fron rear side marker lamps. Required for buses, trucks, semi-trailers, full trailers, and pole trailers.
Front side reflectors
Two amber reflectors located on each side toward the front of buses, and trucks, tractors, semi-trailers, full trailers and pole trailers.
Front turn signals
Two amber lights located to the left and right front of the tractor. Can be above or below headlights. Required on buses, trucks, and truck tractors.
Fuel injectors
Spray the fuel into the combustion chambers.
Fuel lines
Carry the fuel from the pump to the cylinders.
Fuel pump
Delibers the fuel to the engine.
Fuel tank
Hold the fuel.
Changes mechanical energy into electricity to power batteries and other electrical systems.
Provides an alternate safe path for an electrical current if the normal path is accidentally broken.
Ignition switch (or starter)
Supplies electricity t the engine and other systems. When the key is turned, it turns on the accessory circuits. As soon as the engine starts, release the key. If you have a "false start," let the engine cool for 30 seconds before giving it another try.
Used in coupling, a hardened stel pin on a trailer that locks into the fifth wheel.
Leaf spring suspension
Dampens wheel vibration; all the leaves must be intact to previe this comfort. During inspection, look for missing or broken leaves.
License plate lamp
One white light located at the center rear-on buses, trucks, tractor, semi-trailers, full trailers and pole trailers.
Load rating
Refers to the strength of the tire.
Locking device
Keeps the towed trailer and towing tractor together until you're ready to uncouple them. This locking device is called the "locking jaws" and it locks around the shaft of the trailer's kingpin.
Locking jaws
Another name for Locking Device.
Usedto see what is behind and to the sides of the vehicle.
Keeps track of the total miles the vehicle has traveled.
Oil temperature gauge
Guage that shows the temperature of the oil.
Parking lamps
Two amber or white lights located just below the headlights on small buses or trucks.
Pitman arm
A level attached to the steering box-moves the front wheels back and forth.
Separate layer of rubber-cushioned cord.
Power take-off level.
Displays the engine exhaust temperature.
Radial ply
Ply that does not cross at an angle but is laid from bead to bead, across the tire. Radial tires have a number of belts and their construction means the sidewall have less flex and less frictin-which requires less horsepower and saves fuel.
Rear clearance lamps
Two red lights located at the top right and top left of the rear of large trucks and buses, tractors, semi-trailers, full trailers, pole trailers and progecting loads. These lamps outline the overall width. Not required on smaller vechicles.
Rear identification lamps
Three red lights centered on the top rear of large buses, and trucks, large semi-trailers, full trailers, and pole trailers, Not required on smaller vehciles.
Rear reflectors
Two red reflectors located on each side of the lower left of the rear of small and large buses and truck trailers, full trailers and pole trailers.
Rear side marker lamps
One red light located on the lower left and lowers right rear of the side of buses, trucks, semi-trailers, tull trailers, and pole trailers.
Rear side reflectors
Red reflectors located just below the rear side marker lamps- required on buses, trucks, semi-trailers, full trailers, and pole trailers.
Rear tail lamps
Lights located at the rear of the truck - amber in color.
Rear turn signal lamps
Two amber or red lights, each located at teh lower right and lower left of the rear of trucks and buses, tractors, semi-trailers, full trarilers, pole trailers, and converter dollies.
Saddle mounts
A steer assembly taht couples a towed vehicle (trailer or semi-trailer) with the towing vehicle.
Shaft of the kingpin
Coupling device on the trailer around which the jaws of the locking device are placed for a secure connection.
Side reflectors
Two amber reflectors located on each side or near midpoint of the vehicle between the front and rear side reflectors of buses and trucks, large semi-trailers, large full trailers and pole trailers.
Steering axle
An axle taht steers the vehicle- can be powered or nonpowered.
Steering column
Connection between the steering wheel and the steering box.
Steering gear box
The housing between the strreing column that holds the power steering pump to make the wheels turn right and left.
Steering wheel knuckles
Found on Pitman arms and tie-rod ends. Conncetion allows them to swivel.
Stop lamps
The same as "stop lights" Located onthe back of the tractor/trailer - indicate you are stopping the vehicle.
A cable connected to the carburetor which acts like an accelerator, causing the engine to go faster when the knob on the dash board is pulled out. When pushed in, the throttle will slow the engine.
Part of the steering mechanish, connecting devices on the steering column to enable the steering column to turn the wheels of the tractor or truck.
Torsion bar suspension
A steel rod, bar or arm assemble that acts as a spring instead of a leaf or coil spring to create suspension over the rear tractor wheels.
Tow-away operation
Trucking operation offering towing services to disabled vehicles or to transport several tractors/ trucks at one time using one vehicle.
Tow bars
Part of a full trailer that allows the trailer to be coupled to the tractor or another trailer with a locking device and safety chains or a cable to prevent accidental separation.
Tranmission control lever
Another name for Gear Shift
Serise of tie bars and fillets in the outer covering of the tire to improve traction. Traction depth should be at least 2/32 inch.
Used to hold the springs on the frame and hold the springs onto the axle.
Shows the voltage in the alternator or generator; device registering the amount of electricity being produced that goes to the battery.
Air brakes
These brakes use air instead of fluid to stop or break. They require special handling and an additional permit on your CDL.
Air compressor
Compresses air and pumps in into the air tanks, Air brakes use compressed air to brake the vehicle.
Air compressor governor
Maintains constant air pressure in the air tanks - between 100 psi and 125 psi.
Air leakage rate
The rate at which air leaks from the air brakes. Use the air leakage rate to test brake pressure.
Air storage tanks
Also called "air tanks" or "air reservoirs." These tanks hold compressed air produced by the air compressor. These tanks have enough air to stop the vehicle several times, even if the air compressor stops working.
Air tank drains
Air tanks are rquipped with drains, usually located at the bottom of the tank. Oil and water accumulate in the tanks and must be drained daily.
Air tank petcock
A valve on a tank that can be opened to drain the tank.
Alcohol evaporators
Designed to automatically inject alcohol into thesystem to reduce the chace that water in the air brake system wil freeze.
Used to measure the flow of electrical currents.
Stimulant drugs used to stay awake. Also called "Bennies" "speed" or "pep pills" - they are illegal.
Application pressure gauge
Lets the driver know how much air pressure is being applied to the brakes.
Automatic drain
An air tank drain that is activated automatically. From time to time, you will hear these drains blow out the air and any accumulated oil and water.
Axle weight
Weight transmitted to the ground by one axle or one set of axles. Axle weight is not how much the axles themselves weigh! Axles support the vehicle and its load.
Baffled liquid tanks
Tankss with dividers designed to slow down the front-to-back surge.
Dividers in a tanker that keep the load from shifting.
A sloped area that causes the highway or road to slant slightly
Balanced load
Cargo that is evenly distributed from top to bottom, back to front, and side to side.
Bias ply
Tires in which the plies are placed at a criss-crossed angle. This makes the sidewall and the tread very rigid.
Also called "chocks". They prevent trucks from moving unexpectedly; used in testing brakes and loading and coupling trailers.
A method that prevents movement of the cargo in the trailer or any other cargo compartment.
Brake cam shaft
The brake slack adjuster is attached to the push rod at one end and the cam shaft at the other end. When the slack adjuster is pushed, the cam shaft twists, forcing the brake shoes away from each other to press on the side of the brake drum.
Brake chamber
When the driver applies the brake and air is applied to the braking sysytem, air is pumped into the brake chamber and pushes out the "push rod" - which is attached to the "slack adjuster." When the driver takes his or her foot off the brake pedal, the air is released from the brake chamber and the return spring pulls the brake shoes away from the drum.
Brake drums
Located at the ends of the axle. The drums contain the braking mechanish and the wheels are bolted to the drums.
Brake fade
When it takes more and more perssure on the brake pedal to slow the vehicle.
Brake lag distance
Distance the vehicle travels once the brake has been applied and the brakes begin to work.
Brake linings
Brake shoes
These press against the drum, creating enough friction to slow or stop the vehicle.
Brake-door interlock
Applies the brake and holds the throttle in an idle position each time the door is opened.
Bridge traffic control officer
Individual stationed at a drawbridge to direct traffic and to stop traffic just prior to the bridge being raised.
A soild steel divider within the tank
Vehicle that carries more than 15 passengers.
Wires, chains, or other connectors from the tractor to the trailer.
Glass, plastic or metal conatiner used to carry between 5 to 15 gallons of liquid.
Cargo heater
Heater used to keep cargo warm.
Cargo shift
Cargo moves from its original position.
Cargo tank
Tank used to hold liquid or compressed gas.
Carry-on baggage
Luggage, bags, and packages brought onto a bus by passengers. Carry-on baggage must be kept out of the aisle and not impede the movement of passengers.
Center of gravity
The point where weight acts as a force. Center of graveity affects the vehicle's stability.
Centrifugal force
A natural force that pulls liquids or objects away from the center.
The acronym for the Chemical Transportation Emergency Center in Washington, DC. It has a 24-hour toll-free line and has evolved to provide emergency personnel with technical information and expertise about the physical properties of hazardous products. The number is 800-424-9300.
A block (usually made of wood) used to hold a tire in place and keep a vehicle from moving.
Any material that can ignite or burn.
Communicate the risk
Attaching proper placards to the vehicle.
Enclosed space where certain items are kept.
Compressed gas
Gas held under pressure.
The ability to keep any situation or substance from moving from its original site; "containment" of a fire means restriction its movement from its origin; "containment of a liquid" means preventing liquid from spreading farther from its origin, as in a spill.
Controlled braking
Accomplished by squeezing brakes firmly without locking the wheels.
Converter gear
Part of the converter dolly used to couple the tractor and the trailer, or trailer to another trailer.
Includes materials that cause destruction or irreversible damage to human skin tissure on contact - can be liquid or solid.
Connecting two sections of a vehicle or trailer.
Wind currents traveling from side to side - particularly dangerous on mountain roads.
Maintaining materials by freezing.
Where the highway bends in another direction. Usually includes a slight bank, which may cause a load to shift; curves should be taken below the normal speed limit.
Cut-in / Cut-out levels
Governor on the air compressor. When air pressure drops below a certain psi, the governor will cut in and build the pressure back to its necessary level. Then the compressor will automatically cut out.
A pressurized tank designed to hold gases.
In the shape of a cylinder- usually referring to anything long and round.
Dead axles
Axles pulled by the drive axle that do not give power to the wheels. Without the drive axle, these axles would be stationary.
The time the vehicle is scheduled to leave the facility.
Arrival location
Gears that allow each wheel to turn at a different speed on the same axle for easier manageablility while turning.
Disc brakes
Brakes that have a power screw, which is turned when air pressure is applied. This causes the power screw to clap the disc between the caliper's brake lining pads.
Dolly support
The device that holds up the front end of a dolly when it is uncoupled from a tractor.
Dolly tongue
A part of the dolly converter that goes under the trailer, linking it to the tractor or another trailer.
Department of Transportation.
Downhill grade
A steep downward slant in the road, usually around mountains or hill country.
Bridge that can be lifted to accommodate tall water vessels by pulling one-half of the bridge up, thereby interrupting traffic flow.
Drive axle
The axle that provides all of the power to the wheels and pulls the load.
Dry bulk tanks
Tanks that have a high center a gravity, which means the driver will use special care, particulary when rounding curves and when entering or exiting a freeway by using an on-ramp or off-ramp.
Dual air brake system
The truck has two separate air brake systems - the primary system and the secondary system - but only one set of controls.
Dual parking control valves
Some vehicle (mainly buses) have auxiliary air tanks that can be used to release the spring brakes so the vehicle can be moved to a safe place.Vehicles with dual parking control valves have two control knobs on the dash - one is a push-pull know used to apply the spring brakes for normal parking. The other is spring-loaded inthe "out" position.
Dummy coupler
Seals the air brake hose when a connection is not in use.
Loose packaging material
Driving under the influence.
Effective draking distance
Distance the vehicle will travel once the brakes make contact with the drum. With good braking technique and brakes perfectly adjusted on good, dry pavement, a vehicle going 55 mph will travel 150 additonal feet before coming to a complete stop.
An oval shape sometimes found on "fish-eye" mirrors.
Emergency brake system
The system that stops the vehicle in an emergency situation - usually caused by failure of the braking system. The emergency brake system uses parts of the service and parking brake systems.
Emergency exit
Exit used for emergency purposes only.
Emergency line
Air line between the tractor and the trailer. If the service line becomes disconnected, the emergency line becomes the air supply to the trailer brakes. If the emergency line is broken, it will cause the brailer brakes to lock.
Emergency Response Guidebook (ERG)
Used by fire fighters, police officers, industry safety personnnel, and others in the event of an emergency involving HazMat cargo. Book is available through the Department of Transportation.
Engine retarder
Also called "Jake Brake", "Williams Blue Ox Brake" - engine reatrders allow the engine to be used to help slow the vehicle down, particulary if brake fade occurs on a downgrade.
En route
During travel or on the way.
Environmental Protection Agency.
Evasive action
Action taken to avoid an accident, hitting debris on the road, or a dangerous situation - often involves swerving, braking sudden lane chages, etc.
Material or a mixture that can explode.
Fail-safe brakes
Also know as spring brakes. Most commonly used emergency brake and / or parking brake system on tractors and buses. They must be mechanical, because air can leak off.
Federal Motor Carrier Safety Regulations (FMCRS)
Governs the operation of trucks and buses by common, contract and private motor carriers.
Carrying trailers and containers by ship.
Burning signal device - part of safety equipment.
Flash point
The lowest temperature at which a substance can give off flammable vapors that can ignite if the vapors come in contact with a fire or a spark.
Truck or trailer without sides or a top.
FMCSR Part 393
Describes parts and accessories needed to safely operate a commercial motor vehicle.
Foundation brakes
Used at each wheel - parts of the brake that don't rotate. The most common is the S-cam drum brake; wedge and disc brakes less common.
Te rubbing together of two objects which causes resistance.
Front brake limition valve
Vehicle built before 1975 have a front brake limiting valve control switch on the dash. The valve has two postitions - normal and slippery. Putting the valve in the slippery position reduces the normal air pressure to the front brakes by 50% - and in doing so, reduces the braking power of front brakes by 50%.
Front wheel skids (drive wheel skids)
The most common type of skid, resulting from over-braking or over-acceleration - can be stopped by taking foot off accelerator. If road conditions are slippery, push the clutch in.
Device that complete electrical circuit and pervents overheating by breaking the circuit, thus reducing the risk of fire damage.
Gas mask
A safety device carried in vehicle transporting hazardous materials - in case of an accident, the driver will use the gas mask to avoid inhaling poisonous or harmful fumes.
Glad hand
Air hose brake connection between the tractor and the trailer.
Gross vehicle weight (GVW)
Total weight of a single vehicle and its load.
On buses, what passengers use to hold onto while standing in the aisle.
Hazard Class
Indicates the degree of risk associated with a particular material.
Hazardous Material Table
A list of hazardous material outlining federal guidlines.
Hazardous waste manifest
Any cargo containing hazardous waste must be accompanied by a hazardous waste manifest - and this must be signed by the driver/
High center of gravity
The majority of a load's weight is high off the ground.
Identification (ID) number
Number used to identify hazardous materials on shipping papers. ID numbers begin with UN-Except those loads traveling between the United States and Canada, which are identified by an NA number.
Ignition point
Point at which a flammable substance will catch on fire.
The tendency of an object to remain in the the same condition, either in motion or standing still, until it is acted on by an outside force (e.g., applying the brakes to stop a truck)
Infectious substances
May cause disease or death in animals or humans. This includess human and animal excretion, secretions, blood tissue and tissue components.
Inhalation Hazard
A material that can be harmful if inhaled.
The depth of the liquid loaded in your tank, measuring from the bottom of the tank to the surface of the liquid.
Johnson bar
Most of the tractors have a handle attached to (or near) the steering column- also called the "trolly valve" - used to apply the trailer's brakes.
Landing gear
Supports for the front of a trailer when it is not attached to a tractor.
Liquid density
Liquid in a tanker that has a high mass for its volume.
Liquid surge
The movement of a liquid in a tanker, created by the physics of forward motion. When tankers stop, the force of the liquid surge can actually move the entire vehicle several feet forward.
Low air pressure warning signal
On all vehicles equipped with air brakes - signals when air pressure falls below 60 psi.
A document describing cargo in the vehcile.
Manual drain
An air tank drain that is operated by turning a knob (or petcock) a quarter turn -or by pulling a cable.
Modulating control valve
This is controlled by a handle on the dash board and is used to apply the spring brakes gradually. The more the handle is moved, the more the brakes are applied. This valve is designed to use in case servie brakes fail while driving.
National Response Center
Has the ability to contact the proper the enforcement agency and the proper containment or cleaning-up personnel. The National Response Center phone number is 800-424-8802.
Net weight
Weight of a package, not including the packing materials.
Non hazardous material
Material that by itself or in bulk does not create any hazard to health or the environment.
Normal shipping
In a normal stopping situation, you apply pressure to the brake pedal until the vehicle comes to a stop. Pressure is applied smoothly and steadily.
Not otherwise specified.
"Nose factor"
When carrying livestock, remember that your cargo does not have an odor, and you should try to park your vehicle downwind or other vehicle or truckstops to keep everyone happy.
"No zone"
The area to each side of the truck where it is not possible to see approaching traffic.
ORM (Other Regulated Materials)
These materials are not considered hazardous materials, by definition, but are dangerous when transported in commerce, so they must be regulated.
Space in a tanker that allows for liquid loads to expand. Drivers must know outage requirements for each product they haul.
More weight than your veicle can carry or that is legally allowed.
Oxidizing substances
Substances that react with oxygen.
Flat wooden suppoet structure used to group an amount of cargo together for shipping and stacking.
Passenger supervision
Providing passengers information ncecessary for their safety trip.
Permanent tank
A tank that is attached to the vehicle and must be loaded withthe vehicle.
Pintle hook
Used in coupling, at rear of the fifth wheel - used to tow trailers.