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Glossary of Truck Industry Terms N – Q


National Network.
Roadways that allow truck combinations to operate.

National Response Center.
Helps coordinate the emergency forces in response to major chemical hazards.

National System of Interstate Highways.
Also known as the Designated System or National Network. Consists of the interstates and many additional multi-lane, divided highways such as the U.S. routes.

National Transportation Safety Board.
Investigates accidents and offers solutions to prevent future accidents.

Net Ton.
2,000 pounds. Also called a short ton.

Net Weight.
1) The weight of an article clear of packing and container;
2) as applied to a truckload, the weight of the entire contents of the truck; or
3) as applied to a rig, the weight of a tractor trailer when empty or curbweight.

New Entrant.
A motor carrier not domiciled in Mexico that applies for a United States Department of Transportation (DOT) identification number in order to initiate operations in interstate commerce.

New Entrant Registration.
The registration (US DOT number) granted a new entrant before it can begin interstate operations in an 18-month monitoring period. A safety audit must be performed on a new entrant’s operations within 18 months after receipt of its US DOT number and it must be found to have adequate basic safety management controls to continue operating in interstate commerce at the end of the 18-month period.

National Highway Traffic Safety Administration.

Non-Divisible Load.
A unit load which cannot be broken down into smaller, more convenient units for transportation.

Nonresident CDL.
A CDL issued by a State under either of the following two conditions:
(a) To an individual domiciled in a foreign country meeting the requirements of 383.23(b)(1).
(b) To an individual domiciled in another State meeting the requirements of 383.23(b)(2).

A motor vehicle or combination of motor vehicles not defined by the term “commercial motor vehicle (CMV)” in this section.

Non-Negative Specimen.
A urine specimen that is reported as adulterated, substituted, positive (for drug(s) or drug metabolite(s)), and/or invalid.

Non-Synchronized Transmission.
One that does not have thin plates between the gears to assist in shifting. The driver must double-clutch.

North American Standard Inspection.
The methodology used by State CMV safety inspectors to conduct safety inspections of CMVs. This consists of various levels of inspection of the vehicle or driver or both. The inspection criteria are developed by the FMCSA in conjunction with the Commercial Vehicle Safety Alliance (CVSA), an association of States, Canadian Provinces, and Mexico whose members agree to adopt these standards for inspecting CMVs in their jurisdiction.

Nose Mount Trailer.
A refrigerated trailer that has the refrigeration unit at the upper front of the trailer.

National Propane Gas Association.

A non-radioactive hazardous material transported by motor vehicle in types and quantities which require placarding, pursuant to Table 1 or 2 of 49 CFR 172.504.

National Safety Council.

National Trailer Dealers Association.

National Tire Dealers and Retreaders Association.

National Truck Equipment Association.

National Transportation Safety Board.

National Tank Truck Carriers.

Nuclear Regulatory Commission (NRC).
Regulates hazardous materials.

National Used Truck Association.

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Occupational Safety and Health Administration (OSHA).
Regulates hazardous materials.

Shows how many miles or kilometers the rig has been driven.

Off-Duty Time.
Illustrated as (OFF) on the log book. It is any time during which the driver is relieved of all on-duty time responsibilities.

Original Equipment Manufacturers.

Office of Drug and Alcohol Policy and Compliance (ODAPC).
The office in the Office of the Secretary, DOT, that is responsible for coordinating drug and alcohol testing program matters within the Department and providing information concerning the implementation of this part.

Office of Hazardous Materials Transportation (OHMT).
Part of the Research and Special Programs Administration (RSPA) that classifies hazardous materials.

Office of Motor Carriers (OMC).
Part of the Federal Highway Administration (FHWA) that issues and enforces the Federal Motor Carrier Safety Regulations.

Off-Road Recovery.
Using the roadside as an escape path and safely returning to the highway.

A term referring to the difference in path taken by the rear of a vehicle relative to the front when turning. At low speeds the radius of the rear wheel path for a vehicle is smaller than the radius of the front wheel path. Off-tracking increases with increased vehicle wheel-base. An articulated vehicle will exhibit less off-tracking than a non-articulated vehicle of the same wheel-base.

When the rear wheels of a tractor trailer follow a different path than the front wheels when making a turn.

Oil Filter.
Keeps the lubrication system free of impurities.

Oil Level Alarm.
Lights up when the oil level becomes too low for normal operation.

Oil Pan.
Bolted to the bottom of the engine is a container, or reservoir.

Oil Pressure Gauge.
Indicates the oil pressure within the system. If pressure is lost, it means there is not enough lubrication in the system.

Oil Seal.
A device used to retain lubricant in the bearing area of the wheel. The sealing part of the seal is usually made of a resilient material such as synthetic rubber or leather, which is assembled into a wheel or the hub bore.

On-Duty Time. All time from the time a driver begins to work or is required to be in readiness to work until the time the driver is relieved from work and all responsibility for performing work. On duty time shall include:
(1) All time at a plant, terminal, facility, or other property of a motor carrier or shipper, or on any public property, waiting to be dispatched, unless the driver has been relieved from duty by the motor carrier;
(2) All time inspecting, servicing, or conditioning any commercial motor vehicle at any time;
(3) All driving time as defined in the term driving time;
(4) All time, other than driving time, in or upon any commercial motor vehicle except time spent resting in a sleeper berth;
(5) All time loading or unloading a commercial motor vehicle, supervising, or assisting in the loading or unloading, attending a commercial motor vehicle being loaded or unloaded, remaining in readiness to operate the commercial motor vehicle, or in giving or receiving receipts for shipments loaded or unloaded;
(6) All time repairing, obtaining assistance, or remaining in attendance upon a disabled commercial motor vehicle;
(7) All time spent providing a breath sample or urine specimen, including travel time to and from the collection site, in order to comply with the random, reasonable suspicion, post-accident, or follow-up testing required by part 382 of this subchapter when directed by a motor carrier
(8) Performing any other work in the capacity, employ, or service of a motor carrier; and
(9) Performing any compensated work for a person who is not a motor carrier.

On-Duty Time.
Illustrated as (ON) in the log book; this is the time the drive begins work, or must be ready to go to work, until the time he or she is relieved from work of any kind.

One-Way Check Valve.
Prevents air from flowing back into the compressor from the reservoirs.

Ontario Special.
Tractor semi-trailer combination with 8 axles.

Open Dispatch.
The driver goes from the point of origin to a distant point.

Open Top.
Van type trailer with an open roof.

Open Top (Trailer).
A truck or trailer body with sides but without any permanent top, often used for heavy equipment that must be lowered into place by crane.

Order For Service.
A document authorizing you to transport an individual shipper’s household goods.

Order Notify Bill Of Lading.
A bill of lading that permits the shipper to collect payment before the shipment reaches the destination. The driver must pick up the consignee’s copy of the bill of lading before he or she delivers the shipment.

Order Notify Shipment.
One in which payment for the goods is made when the driver gets a copy of the Order Notify Bill of Lading from the consignee.

Ordinary Trailer Axle.
Connects the trailer wheels to the trailer body.

Originating, Or Pickup, Carrier.
The carrier that first accepts the shipment from the shipper.

Outer Bridge.
The distance from the center of the steering axle to the center of the last axle in the combination. Determines weight limits.

Out-Of-Service Order.
A declaration by an authorized enforcement officer of a Federal, State, Canadian, Mexican, or local jurisdiction that a driver, a commercial motor vehicle, or a motor carrier operation, is out-of-service  pursuant to Sections 386.72, 392.5, 395.13, 396.9, or compatible laws, or the North American Uniform Out-of-service Criteria.

Used for extra support of wide loads.

Freight in excess of the quantity or amount shown on the bill of lading or other shipping document.

Overdimensional (OD).
Term which denotes a vehicle that exceeds a state’s maximum, allowable length, width, height, and/or weight.

A transmission gear ratio where the engine crankshaft turns at a slower rate than the vehicle drive shaft thus the engine speed is reduced for more economical high-speed driving.

Refers to a condition in which the vehicle’s transmission is in a gear having a ratio greater than 1:1, that is, the engine crank shaft turns at a slower rate than the vehicle drive shaft.

Driving at a speed that will not let you stop within your sight distance.

Overdriving The Headlights.
Driving at a speed that will not permit you to stop your vehicle within the distance you can see ahead.

Overload Spring.
An additional spring on a leaf spring suspension system that is used in trucks to increase the suspension stiffness at high load. Also called helper springs.

Overlength Load.
Cargo that is longer than the legal limit permits.

Overriding The Governor (Overspeeding).
When the weight of the vehicle drives the engine beyond governed speed. Happens on hills when vehicle is not in allow enough gear and is not supplemented as necessary by light, steady brake application. The governor does not control the engine speed when the vehicle is driving the engine.

Oversized Vehicle.
Any vehicle whose weight and/or dimensions exceeds state regulations.

Turning the wheels beyond the intended path of travel or more sharply than the vehicle can handle.

Over-The-Counter Drugs.
Drugs that don’t need a prescription, but still may have side effects like drowsiness that you should be aware of.

Cargo is hauled on regular routes. Drivers may be away for a week or more.

Overweight Load.
Cargo that weighs more than the legal limit permits.

Overwidth Load.
Cargo that is wider than the legal limit permits.

A trucker who owns and operates his own tractor (sometimes trailer) and is leased to a motor carrier or private carrier. Also called an independent contractor.

Driver who owns and operates his own truck; he may be a common carrier, contract carrier or exempt carrier; such contractor may lease vehicle and driver to another carrier.

Oxidizing Adulterant.
A substance that acts alone or in combination with other substances to oxidize drugs or drug metabolites to prevent the detection of the drug or drug metabolites, or affects the reagents in either the initial or confirmatory drug test.

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Packing List.
A detailed specification of packed goods.

Packing Slip.
A detailed list of packed goods that is prepared by the shipper.

A portable platform for holding material for storage or transportation.

Pallet Jacks.
Used for loading palletized cargo.

Stacked on pallets.

Parallel Parking.
Parking in a straight line behind one vehicle and in front of another vehicle.

Parking Brake.
Used when the vehicle is not running. To check that it is working, put on the brake and engage the transmission to see if it holds.

Parking Brake Control Valve.
A flip switch or push-pull knob that lets the driver put on the parking brake. Use this valve only when the vehicle is parked.

Parking Brake Valve.
The valve that directly controls the application of spring brakes on the tractor. It appears as the yellow knob on the dashboard.

Parking Brake System.
Is used to hold the rig in place when it is parked.

The cargo that a commercial vehicle hauls, or the weight of that cargo, subject to local definition.

The cargo or freight that a vehicle hauls.

Peddle Run.
Local pickup and delivery operation: the freight is usually hauled from the terminal to separate destinations in the nearby areas and freight is also picked up along the way and brought back to the terminal.

The conscious understanding that an event has taken place.

Performing (A Safety-Sensitive Function).
A driver is considered to be performing a safety-sensitive function during any period in which he or she is actually performing, ready to perform, or immediately available to perform any safety-sensitive functions.

Any individual within the 5th percentile female adult through the 95th percentile male adult of anthropometric measures as described by the 1962 Health Examination Survey, “Weight, Height and Selected Body Dimensions of adults, United States 1960-1962” which is incorporated by reference.

A party petitioning to overturn a determination in a driver qualification proceeding.

Semi-trailer built with reinforcements to withstand transport by a railroad flatcar. It is also another name for a spring brake chamber.

Transportation of a highway trailer on a railway flat car.

Electrical cable used to transmit power from the tractor to the trailer; it resembles the coiled tail of a pig.

Slang for the electrical cable used to transmit power from the tractor to the trailer.

Pinion Gear.
At the rear end of the propeller shaft is a short shaft with a small gear at the end.

Pintle Hook.
Coupling device used in double trailer, triple trailer and truck-trailer combinations. It has a curved, fixed towing horn and an upper latch that opens to accept the draw bar eye of a trailer or dolly.

A device that moves up and down in the engine cylinder and provides power to the crankshaft.

Pitman Arm.
Lever that converts rotary output from steering box to linear movement of a drag link.

10 ¾ inches square and turned upright on a point in a diamond shape. Federal laws specify when placards must be displayed on vehicles transporting hazardous materials.

Plane Mirror.
A flat mirror for seeing to the rear of the rig. Point of reference. A stationary object that you spot or use as a target when you are driving.

Platform Body.
Truck or trailer body with a floor, but no sides or roof. Also called a stake truck.

Any free movement of components.

Point of Origin.
The terminal at which a shipment is received by a transportation line from the shipper.

Pole Trailer.
Carries long, narrow cargo. A pole trailer can be telescoped, or made longer or shorter to fit the load. Cargo may be poles, timbers, logs, steel girders, or concrete beams.

Political Subdivision.
A municipality, public agency or other instrumentality of one or more States, or a public corporation, board, or commission established under the laws of one ore more States.

Pop-off Valve.
Pressure relief valve fitted in the air tanks to avoid over-pressurization.

Port of Entry.
Locations where the driver must stop and prove the carrier has authority to operate in the state.

Positive Rate.
The number of positive results for random controlled substances tests conducted under this part plus the number of refusals of random controlled substances tests required by this part, divided by the total of random controlled substances tests conducted under this part plus the number of refusals of random tests required by this part.

Posted Bridges.
Many bridges have special weight restrictions. Some fines are as much as $10,000.

Post-Trip Inspection.
A thorough check of the rig at the end of a trip.

Pot Belly Trailers.
Name for double-deck or triple-deck livestock trailer. Also called Possum Belly Trailer.

Power Divider.
A part of the dual axle drive system designed to transfer power between two or more axles of a tandem axle arrangement.

Power-Lift Tail Gate.
A power-operated tailgate capable of lifting load from street level to the level of the truck or trailer floor.

Power Skid.
A skid that happens when the drive wheels spin and the rear of the tractor moves sideways.

Power Steering.
Lets the driver control the tractor with less effort and stress.

Power Steering Fluid.
Makes the steering easier to turn and should be checked during regular maintenance.

Power Stroke.
Phase of the four-stroke cycle when fuel is ignited and combustion take place.

The series of components that make up the power transmission and transfer engine power to wheels; consists of engine, clutch, transmission, drive shafts and drive axles.

Powered Axle.
Commonly called a live axle.

Prepaid Shipments.
Ones in which the transportation charges are paid at the shipping point.

Prescription Drugs.
Are drugs that are prescribed by a doctor.

Pressure Points.
Arteries that supply blood to the body.

Pre-Trip Inspection.
A systematic parts and system check made before each trip.

Preventable Accident on the Part of a Motor Carrier.
An accident
(1) That involved a commercial motor vehicle, and
(2) That could have been averted but for an act, or failure to act, by the motor carrier or the driver.

Preventive Maintenance.
Servicing that is done at regular intervals on a truck.

Primary Specimen.
In drug testing, the urine specimen bottle that is opened and tested by a first laboratory to determine whether the employee has a drug or drug metabolite in his or her system; and for the purpose of validity testing. The primary specimen is distinguished from the split specimen, defined in this section.

Primary Vehicle Controls.
Allow the driver to control the truck.

Principal Place of Business.
The single location designated by the motor carrier, normally its headquarters, of purposes of identification under this subchapter. The motor carrier must make records required by parts 382, 387, 390, 391, 395, 396, and 397 of this subchapter available for inspection at this location within 48 hours (Saturdays, Sundays and Federal holidays excluded) after a request has been made by a special agent or authorized representative of the Federal Highway Administration.

Principal Place of Business.
The main office of the carrier where all records are kept.

Private Carrier.
Business which operates trucks primarily for the purpose of transporting it s own products and raw materials.

Private Motor Carrier.
A person who provides transportation of property or passengers, by commercial motor vehicle, and is not a for-hire motor carrier.

Private Motor Carrier of Passengers (business).
A private motor carrier engaged in the interstate transportation of passengers which is provided in the furtherance of a commercial enterprise and is not available to the public at large.

Private Motor Carrier of Passengers (non-business).
A private motor carrier involved in the interstate transportation of passengers that does not otherwise meet the definition of a private motor carrier of passengers (business).

Pro Numbers.
Preprinted numbers on freight bills that are often used to identify the freight bill.

Progressive Shifting.
Is shifting before you reach the maximum governed RPM.

Proof of Delivery.
A motor carrier establishes proof of delivery from delivery receipt copy of freight bill signed by consignee at time of delivery. This is legal proof of delivery.

Property Damage.
Damage to or loss of use of tangible property.

Property Broker.
A company that arranges for the truck transportation of cargo belonging to others utilizing for-hire carriers to provide the actual truck transportation. The broker does not assume responsibility for the cargo and usually does not take possession of the cargo. Brokers must obtain operating authority from the FMCSA.

Provisional Certification of Registration.
The registration under 368.6 that the FMCSA grants to a Mexico-domiciled motor carrier to provide interstate transportation of property within the United States solely within the municipalities along the United States-Mexico border and the commercial zones of such municipalities. It is provisional because it will be revoked if the registrant does not demonstrate that it is exercising basic safety management controls during the safety monitoring period established in this subpart.

Provisional Operating Authority.
The registration under 365.507 that the FMCSA grants to a Mexico-domiciled motor carrier to provide interstate transportation within the United States beyond the municipalities along the United States –Mexico border and the commercial zones of such municipalities. It is provisional because it will be revoked if the registrant is not assigned a Satisfactory safety rating following a compliance review conducted during the safety monitoring period established in this subpart.

PSI (Pounds per Square Inch).
The unit of measurement for tire air pressure, air brake system pressure and turbocharger boost.

PTO (Power Takeoff).
A device designed to transmit engine power to auxiliary equipment such as concrete mixer or refuse packer.

Public Liability.
Liability for bodily injury or property damage and includes liability for environmental restoration.

Public Relations.
How a truck driver gets along with the public.

Pull Trailer.
Full trailer supported by axles front and rear with a variety of tongue lengths.

Pulpwood Trailer.
A trailer or semitrailer that is designed exclusively for harvesting logs or pulpwood and constructed with a skeletal frame with no means for attachment of a solid bed, body, or container.

Slang term for short semi-trailer used in combination with dolly and another semi-trailer to create twin trailers.

Pup Trailer.
Short semi-trailer, usually between 26 and 32 feet long, with a single axle.

A rod designed to transmit linear displacement to an actuating mechanism when in compression.

Pusher Axle.
Powered rear axle of a tandem arrangement, where the forward axles are non-powered or “dead.”

Pusher Tandem.
The rear axle is powered (live) and the forward axle is not powered (dead). The forward axle must have a drop center so the drive shaft can be attached to the live axle.

Instrument installed to monitor the temperature of the exhaust gases of a diesel engine.

Pyrometer Warning.
Lights up when exhaust temperatures are too high.

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Qualification Training.
The training required in order for a collector, BAT, MRO, SAP, or STT to be qualified to perform their functions in the DOT drug and alcohol testing program. Qualification training may be provided by any appropriate means (e.g. classroom instruction, Internet application, CD-ROM video).

Quick Release Valve.
Allows the brakes to release swiftly. When you remove your foot from the brakes, air escapes from the chambers into the atmosphere.

Quick Release Valves.
Valves designed to accelerate the release of air pressure from the brake chambers of the air brake system.

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