Partners in Business: Owner-operator glossary

trucks On I-20-59

ACCOUNTS PAYABLE. Amounts owed by a business to its creditors.

ACCOUNTS RECEIVABLE. Amounts owed to a business by customers.

ADDITIVE. Solutions added to diesel fuel during cold weather to reduce the possibility of waxing and gelling or in all weathers to enhance lubricity.

ADJUSTED GROSS INCOME (AGI). The income on which an individual calculates income tax. For a sole proprietorship, AGI minus deductible business expenses equals amount taxed.

ADVANCE. Money paid to an owner-operator before he hauls a load. This money typically is used to cover some of the expenses involved in the trip (e.g., fuel, tolls, lumpers, gate fees) and is subtracted from the owner-operator’s next settlement.

AERODYNAMICS. The action of air on a moving object. The more aerodynamic a truck, the more it is designed for minimal air resistance. All other factors being equal, this translates into better fuel economy.

AGENT. Generally, a person or organization authorized to conduct business on behalf of another person or organization; also, a common carrier that appoints agents to secure freight on behalf of the carrier. In some cases, an agent also works directly with the owner-operator to match available freight with his truck. Agents typically are independent contractors, not employees of the carrier. A leased owner-operator also can be considered an agent of his carrier.

ASSET. Any type of property, personal or real, that can be sold within one year.

ATBS CODE. A unique identifier associated with ATBS. It is the first four digits of the client’s last name followed by the last four digits of the client’s Social Security Number.


BACKHAUL. Return trip, or the freight secured for the return trip.

BALANCE SHEET. A document that lists all the assets and liabilities of a person or business.

BILL OF LADING (BOL). A written contract between shipper and carrier that identifies the freight, its origin and destination, its receiver and the terms of the agreement, including freight charges. Same as freight bill; not the same as manifest.

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BILL OF SALE. A contract for the sale of goods.

BOBTAIL. A tractor without a trailer attached.

BOBTAIL INSURANCE. Valid insurance when a trucker has an accident while running without a trailer. Not the same as non-trucking use insurance.

BUDGET. A document that lists income and expenses, enabling a person or business to allocate available cash among various expenses. See CASH FLOW STATEMENT.

“C” CORPORATION. A legal structure designed for large, complex businesses. See CORPORATION and “S” CORPORATION.

CAB CARD. A certificate of registration issued to a vehicle. A cab card reflects the base plate issued to that vehicle and the vehicle’s year, make and VIN number, as well as the jurisdiction that the motor carrier has apportioned in.

CAPITAL. Net worth; money available to invest in equipment that will produce more money over time.

CARGO INSURANCE. Insurance designed to cover lost or damaged freight. Carriers typically provide cargo insurance for leased operators, but owner-operators with their own operating authority must provide their own. Federal regulations set the minimum levels required. Not the same as physical damage insurance.


CASH FLOW STATEMENT. A document that shows the difference between cash brought in and cash paid out during a specific period. A negative cash flow is unsustainable.

CASING. The tire structure, excepting tread and sidewall rubber.

CDL. Commercial driver’s license.

CHASSIS. The part of a vehicle that includes the frame, suspension system, wheels, steering mechanism, etc., but not the body and engine.

CHARGEBACK. Items for which the carrier pays but then later charges back to the leased owner-operator, usually as a deduction from pay.

CLAIM. A charge against a carrier made by a shipper or other party for freight lost or damaged allegedly while the freight was in the carrier’s possession.

CLEAT. A strip of wood or metal used for additional strength, to prevent warping, or to hold something in place.

CMV. Commercial motor vehicle.

COLLATERAL. A pledge of security for borrowing money; something that a lender can seize if the borrower defaults on the loan agreement.

COMMODITY. Generally, any goods shipped; most often used to refer to general commodities, a loose term for a wide variety of unpackaged freight such as grain and ore.

COMMON CARRIER. A business that engages in for-hire transportation of goods across the entire universe of shippers; a trucking company with services available to all. For interstate operations, only the U.S. DOT can issue common carrier authority. See CONTRACT CARRIER.

CONSIGNEE. The person or firm to which freight is shipped; the receiver.

CONTAINERIZED SHIPPING. Transport of cargo containers that are transferred easily among trucks, trains and ships.

CONTRACT CARRIER. A trucking company that engages in for-hire transportation of goods for one or more specific shippers; a trucking company with services not available to all. See COMMON CARRIER.

CORE. On a radiator, a tubular fin structure acting as a heat exchanger for engine cooling fluids.

CORPORATION. A business structure in which the company is separate from its owners. A corporation enjoys tax benefits and legal protections not available to other forms of business. See “C” CORPORATION and “S” CORPORATION.

COST PER DAY. The business expenses you incur daily, whether you drive or not. It is calculated by dividing your weekly fixed expenses by seven.

COST PER MILE (CPM). The cost of operating a trucking business per mile traveled. CPM is calculated by dividing cost by the number of miles driven. Usually expressed in cents, it sometimes is called cents per mile.

COWL. Metal structure supporting dash and windshield.

CRANKCASE. Engine part that houses the crankshaft and other moving parts.

CRANKSHAFT. A shaft within the engine having one or more cranks for transmitting motion; the connecting rods transmit motion between the pistons and crankshaft.

CSA. The Compliance, Safety, Accountability safety ranking and enforcement program of the Federal Motor Carrier Safety Administration.

CUSTOM HOUSE. The government office where duties, tolls, import or export taxes are paid.

CYLINDER. A chamber in the engine block that contains a piston.

DEADHEADING. Running without cargo.

DEDICATED RUN. A run that involves hauling the same type of freight to and from the same locations on a regular schedule; also, hauling freight to and from the same shipper and receiver on a regular basis, regardless of location.

DEDUCTIBLE. Money paid out of pocket by an insured person before the insurance company pays a claim.

DEDUCTIBLE EXPENSES. Business expenses that are allowable deductions from adjusted gross income, thus reducing taxable income. Deductible business expenses are reported on IRS Schedule C.

DELIVERY RECEIPT. The record to show that goods were delivered. Drivers usually have delivery receipts signed by receivers to show that the delivery was made.

DEPARTMENT OF TRANSPORTATION (DOT). The federal agency responsible for the administration of the Federal Motor Carrier Safety Regulations.

DEPRECIATION. An expense allowance made on your taxes for wear and tear on an asset over its estimated useful life.

DISABILITY INSURANCE. Insurance that pays a weekly benefit plus medical expenses if illness or injury prevents the insured person from working. Not the same as occupational-accident insurance.

DISPATCH. A service that schedules and coordinates freight pickup and delivery.

DOT. U.S. Department of Transportation.

DRAYAGE. The charge made for carting, draying or trucking freight, often at a dock or the Mexican border.

DRIVE AXLE. An axle that transmits power to the wheels.

DRIVE LINE. Refers to the drive shaft and universal joints, etc., that connect the transmission to the differential gears on a drive axle.

DRIVESHAFT. A heavy-duty tube that connects the transmission to the rear-end assembly of the tractor.

DRIVETRAIN. A series of connected mechanical parts for transmitting motion. The drivetrain includes all of the parts used to supply motion, including transmission, drive shaft, universal joints, differentials, inter-axle differential and axles.

DRIVERS. (Slang) The drive wheels of a tractor.


DUTY. A tax levied by a government on imports and exports.

DYNAMOMETER. A device used to measure the performance of the engine and drivetrain. Often called a dyno.

EIN. Employer Identification Number, also known as a federal tax identification number. It is used to identify a business entity for tax purposes. It is required only if you are operating as a corporation or LLP or if you file your own 2290 Federal Highway Use Tax form.

ELECTRONIC CONTROL MODULE (ECM). A device that monitors engine performance and records some diagnostics. Also called an electronic control unit (ECU).

ELECTRONIC LOGGING DEVICE (ELD). Current terminology for an electronic device connected to a truck’s ECM, paired with a driver input device, that allows for electronic logging of duty status records and hours of service monitoring.

ELEVATOR. (Slang) A hydraulic or electrically powered end gate on a truck or trailer.

ENDORSEMENT. Special qualification required of CDL holders for hauling a specific type of commodity, such as hazardous materials, or for operating a specific type of equipment.

ESCROW. Money held in reserve. It can be money held by a carrier in the name of a leased owner-operator to protect the company in case the contractor quits while in debt to the company; to provide money for the owner-operator’s use in an emergency; or to reimburse the carrier for items bought by the company on the owner-operator’s behalf.

ESTIMATED TAX. Taxes paid in advance by self-employed people. The IRS requires owner-operators to guess how much tax they will owe each year based on the previous year’s income or projections and to make quarterly payments based on that estimate.

ETHER. Substance used as a starting aid for diesel engines in freezing or subfreezing weather.

EXEMPT CARRIER. A carrier that hauls commodities exempt from DOT regulation.

EXEMPT COMMODITIES. Freight exempt from DOT regulation, most commonly fresh fruits and vegetables.

EXHAUST MANIFOLD. That part of the exhaust system that carries the exhaust gases from the cylinders to the exhaust pipe.

EXHAUST PIPE. Pipe connected to muffler through which exhaust gases are released.

EXPANDABLE (TRAILER). Flatbed trailer that can be expanded beyond its regular length to carry larger shipments.


FEDERAL HIGHWAY USE TAX. One of the main sources of funds for the national highway construction program, paid by all carriers for each heavy vehicle that runs in interstate transport, including trucks and buses, and based on the size and weight of the vehicle. All independent owner-operators and most leased owner-operators are responsible for paying their own Federal Highway Use Tax, which is reported on IRS Form 2290.

FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION (FMCSA). DOT division responsible for administering and enforcing the Federal Motor Carrier Safety Regulations and the hazardous materials regulations.

FEDERAL MOTOR CARRIER SAFETY REGULATIONS. The regulations that govern the operation of trucks and buses in interstate or foreign commerce by common, contract and private motor carriers. The FMCSRs specify insurance requirements, driver qualifications, hours of service, accident reporting procedures, proper vehicle inspection and repair procedure, and proper parts and accessories for safe operation.

FISHY-BACK. (Slang) Transportation of truck trailers or highway freight containers on ships or barges.

FIXED COSTS. Predictable, consistent costs that do not vary by the number of miles run – for example, tractor payments and insurance payments. See VARIABLE COSTS.

FLOAT. Flatbed semi-trailer.



FREIGHT CHARGE. Payment due for freight transportation.

FUEL INJECTOR. The device that injects a mist of fuel into the combustion chamber.

FUEL PUMP. Pump that moves fuel from the fuel tank to the engine.

FUEL SURCHARGE. Extra charges included on the carrier’s invoice for excessive fuel costs.

FUEL TAX. Any federal or state tax levied on fuel to pay for the use and maintenance of highways and roads. The federal tax remains constant, but state taxes vary and usually are based on the number of miles run in a state.

GBL. Government bill of lading.

GELLING. As diesel fuel gets cold, it has a tendency to harden or gel.

GEORGIA OVERDRIVE. (Slang) Driving a truck down a hill with the transmission out of gear (an unsafe and illegal practice).

GLADHANDS. Connectors mounted on the front of a trailer for connecting airlines from the tractor.

GOOSENECK. The curved section of a trailer frame that includes the kingpin and the fifth wheel apron.

GROSS COMBINATION WEIGHT (GCW). Combined weight of the tractor, trailer and cargo.

GUSSETS. That part of the frame where the cross members are bolted to the frame rails.

HAZMAT. Hazardous material; any substance the U.S. government has determined to be dangerous to public health when packaged or transported improperly.

HEADACHE RACK. (Slang) Heavy bulkhead mounted behind the cab to protect it from a shifting load.

HI-LOW. Nickname for a forklift truck.

HHG. Household goods. Usually refers to the calculation of miles on which freight rates are based, used as a standard in the trucking industry.


ICC. Interstate Commerce Commission.

INBOUND FREIGHT. Freight moving toward the speaker’s point from another point.

INDEPENDENT. An owner-operator who has his own operating authority and is not leased to a carrier, generally relying on no one but himself to find and transport freight.

INDIVIDUAL RETIREMENT ACCOUNT (IRA). A retirement savings vehicle that allows an individual to make tax-deferred contributions. Contributions are tax deductible, but the payout is taxed at the prevailing rate at the time of payout. See ROTH IRA.


INSURANCE AGENT. A representative of one or more insurance companies. An independent agent represents more than one company; a captive agent represents only one company.

INTEREST. The cost of borrowing money expressed as a percentage, usually an annual percentage rate (APR).

INTERMODAL TRANSPORTATION. Movement of goods involving more than one mode of shipment on a single freight bill – for example, both rail and truck.

IRONS. (Slang) Tire chains.

JACKING. (Slang) Turning a tractor while backing so as to cause the trailer to assume a jackknife position. Combines with chasing to allow the trailer to be steered along the prescribed path.

JAKE BRAKE. (Slang) Specifically refers to the original engine brake made by Jacobs Vehicle Systems. An engine brake is an auxiliary braking device on a tractor. It builds up back pressure in the engine by preventing the exhaust from escaping so that the engine slows.

JACKRABBIT START. (Slang) A sudden start.

JOINTS. (Slang) Refers to double and triple trailer combinations.

JUST-IN-TIME DELIVERY (JIT). An inventory control system in which freight is used as soon as it arrives at its destination. To work, just-in-time delivery mandates that freight not arrive early. Sometimes called “rolling inventory” when the freight is left on trailers due to delayed unloading.

KINGPIN. The bolt-like device on the underside of the front of a semi-trailer that fits into the tractor’s fifth wheel to couple the tractor and the trailer together.

LANDING GEAR. The support legs that hold up the front end of a semi-trailer when it is disconnected from a tractor.

LAYOVER. Non-driving time between loads while under dispatch, whether it’s a scheduled rest or time spent waiting for instructions.

LEASE. The contract between an owner-operator and a motor carrier for the purpose of hauling freight booked by the carrier. Leases spell out the responsibilities of each party.

LEASING. An alternative to traditional equipment financing, whereby the lessee pays rent on the equipment and makes monthly payments. See TRAC LEASE.

LESSEE. The party to a leasing agreement who has possession and control of a vehicle owned by another.

LESSOR. The party to a leasing agreement who grants possession and control of a vehicle to another.

LESS THAN TRUCKLOAD (LTL). Type of hauling in which multiple shipments share one trailer.

LIABILITY. Outstanding debt.

LIABILITY INSURANCE. Insurance that covers property damage and bodily injury to another party. Includes bobtail, non-trucking use and unladen. See PRIMARY LIABILITY INSURANCE.

LIMITED LIABILITY COMPANY (LLC). Business structure that offers limited protection for the owners. Profits pass through the owners’ personal income tax returns.

LIMITED LIABILITY PARTNERSHIP (LLP). A business structure not recommended for owner-operators.

MANIFEST. A document describing the contents of a shipment. Often incorrectly used interchangeably with “bill of lading,” which is a much more comprehensive document.

MISCELLANEOUS PAY. Pay you receive in addition to your pay per mile or load. It could include your fuel surcharge, stop pay or detention pay.

MPG. Miles per gallon.

MPH. Miles per hour.

MUTUAL FUND. An investment pool whose money is in stocks, bonds or other assets. Buying shares of the fund gives you a stake in those assets.

NET CASH. The cash you have left after all your business and personal expenses have been covered.

NET INCOME. The amount left over after expenses have been subtracted from revenue. Also called earnings or net earnings.

NET PROFIT. Same as net income or profit.

NET TON. 2,000 pounds (also called a short ton).

NET WORTH. The difference between a person’s assets and liabilities. Also called owner’s equity.

NO. 1 DIESEL. Cold weather fuel.

NO. 2 DIESEL. Normal weather fuel.

NON-TRUCKING USE INSURANCE. Liability insurance that covers an owner-operator not under dispatch. Not the same as bobtail insurance.

NOS. Not Otherwise Specified, a term used in describing hazardous materials.


OCCUPATIONAL-ACCIDENT INSURANCE. Insurance that pays a weekly benefit plus medical expenses if injury on the job prevents the insured person from working. Not the same as disability insurance.

OFF-DUTY TIME. Time specified in the hours-of-service regulations, and on a log book page, where the driver is relieved of all work duties and has no responsibilities to the truck.

OIL SEAL. A device used to retain lubricant in the bearing area of the wheel.

ON-DUTY TIME. The time specified in the hours-of-service regulations and on a logbook page, where the driver is working, or is in readiness to work.

OPERATING AUTHORITY. Permission to operate granted to interstate common carriers by the U.S. DOT. When an owner-operator leases on with a company, that company’s authority automatically extends to the owner-operator. Independent owner-operators, however, must establish their own authority.

OPERATIONS. The department of a carrier responsible for finding loads, dispatching trucks and handling customer service.

OTR. Over the road. Refers to operations requiring an overnight trip.

OVER, SHORT AND DAMAGED (OS&D). Discrepancies between freight on hand and freight shown on the bill. Freight not covered by billing is over. If some is missing, it is short. Freight received in bad condition is damaged.

OVER-THE-ROAD OPERATIONS (OTR). The interstate transporting of freight for long distances, whether nationally or regionally. Also referred to as long-haul trucking.

OVERDIMENSIONAL FREIGHT. Freight that is legally too heavy, too long or too tall, thus requiring a special permit.

OWNER-OPERATOR. A small-business owner involved in for-hire transportation who owns one or more commercial vehicles and still drives.

OWNER-OPERATOR INDEPENDENT DRIVERS ASSOCIATION (OOIDA). An association primarily for leased owner-operators and independents.

PAJAMA WAGON. (Slang) Sleeper tractor.

PARTNERSHIP. A business owned by two or more people, each of whom is taxed individually.

PAYABLES. Accounts payable.

PAYLOAD. The weight of the cargo as the basis for the revenue to be paid for that shipment.

PERCENTAGE OF REVENUE (COSTS). The portion of your revenue each cost represents. It is calculated by dividing the individual cost by the total revenue.

PERCENTAGE OF REVENUE (PAY). A form of compensation where the owner-operator receives a percentage of the gross revenue paid to the carrier.

PER DIEM. Latin for “per day.” In tax law, those business expenses a person can claim each work day without that money being subject to income tax. For professional drivers, the per diem commonly means the daily tax allowance for meals on the road.

PHYSICAL DAMAGE INSURANCE. Insurance that covers damage to an owner-operator’s equipment from an accident involving another vehicle. The law does not require a truck owner to have physical damage insurance, but the lien holder usually does. Not the same as cargo insurance.

PIG TRAILER. Transported on flat rail car.

PIGTAIL. (Slang) Electrical cable used to transmit power from the tractor to trailer.

PINTLE HOOK. Coupling device at rear of truck for the purpose of towing trailers.

PREVENTIVE MAINTENANCE (PM). Checking and servicing equipment according to a planned schedule – for example, each haul or each 10,000 miles.

PRIMARY LIABILITY INSURANCE. Insurance required by law to protect the insured in case of harm against another person, such as property damage or injury. Carriers are required to have such insurance and may deduct the premiums from an owner-operator’s settlement.

PRIVATE CARRIER. A company that transports only its own goods over the road without contracting with another company. Many grocery, retail and restaurant chains are private carriers.

PRO NUMBER. The identifying number on a bill of lading for invoicing and tracking purposes.

PROFIT AND LOSS STATEMENT (P&L). A detailed report of how much money a business made or lost during a specific period.

PROOF OF DELIVERY (POD). A document to show that delivery was made, such as a bill of lading or delivery receipt signed by the consignee/receiver.

PROFESSIONAL TRUCK DRIVER INSTITUTE. PTDI develops standards for training tractor-trailer drivers, certifies training courses, and provides truck driver training educational products. It is an arm of the Truckload Carriers Association.

PROGRESSIVE SHIFTING. A fuel-efficient method of shifting gears by accelerating just enough to gain the minimum rpms to shift into the next gear. This also saves wear on the mechanical components of the truck.

PSP. The Pre-Employment Screening Program of the Federal Motor Carrier Safety Administration, making driver inspection and crash histories available to motor carriers for pre-hire/-lease screening purposes.

PULL THE PIN. (Slang) Release the fifth wheel lock.

PUP. (Slang) A short four-wheel trailer pulled behind a semi-trailer or a straight truck.

PUT ON THE AIR. (Slang) Apply the brakes.

PUT ON THE IRONS. (Slang) Put on the tire chains.

QUALIFIED RETIREMENT ACCOUNT. A bank account set up by an individual as a retirement plan according to IRS rules. In most such plans, contributions are tax- deductible, but payouts are taxed at the prevailing tax rate at the time of payout.

RADIATOR. A device comprised of tubes and fins through which circulating water passes to give off excess heat and thus cool the engine.

RATE. The tariff or charges for hauling freight.


REGULATOR. Voltage regulator.


RESIDUAL VALUE. The amount owed to the lessor at the end of a TRAC LEASE.

RETIREMENT ACCOUNT. An account that allows you to make tax-deductible contributions that only can be withdrawn, penalty free, after a certain age.

REVENUE. The total amount of money an owner-operator earns before accounting for expenses. Also known as gross income.

RIDE SHOTGUN. (Slang) To ride as co-driver in the passenger seat of the tractor.

RIG. (Slang) Truck; tractor/semi-trailer; truck and full trailer; other combination vehicle.

RISK MANAGEMENT. The department of a carrier that monitors and controls the carrier’s exposure to risk, usually from truck accidents.

ROTH IRA. An Individual Retirement Account with a tax status that works in reverse to that of a traditional IRA. An individual can contribute up to $2,000 a year, taxable at the current rate; eventual payouts are tax-free.

“S” CORPORATION. A structure designed for small businesses with 35 or fewer shareholders. To maintain “S” status, the business must follow certain guidelines.

SAE. The Society of Automotive Engineers. Establishes standards for parts, components, etc., on some motor vehicles.

SATELLITE SYSTEM. A method of tracking the exact location of a truck by means of satellite tracking devices.

SATELLITE TERMINALS. Refers to truck terminals.

SCHEDULE C. The IRS form that lists all business income and expenses. The difference, whether profit or loss, is reported on Form 1040. All sole proprietors must submit a Schedule C, “Profit or Loss Business Sole Proprietorship,” with their 1040.

SELF-EMPLOYMENT TAX. Social Security and Medicare tax paid by the self-employed, such as an owner-operator.

SEMI. (Slang) A tractor-trailer combination.

SETTLEMENT. The record of an owner-operator’s net revenue for a certain period, prepared by the trucking company he leases to. A settlement shows total revenue earned minus company charges.

SMOKER. (Slang) Tractor emitting excessive exhaust smoke.

SNELLEN CHART. An eye examination chart usually used during a DOT physical to determine if a person meets visual requirements.

SOLE PROPRIETORSHIP. Business structure in which one person is the owner. This is the simplest way to structure a business and the method recommended for most owner-operators.

SPECIALIZED CARRIER. A carrier that transports only a particular type of freight, such as trade exhibits or construction equipment.

SPECS, SPEC’ING. Specs are a detailed description of a truck’s standard components and optional features. Spec’ing is the act of specifying such components and features.

SPOT THE TRAILER. (Slang) To park and uncouple a trailer at a designated location.

STRAIGHT TRUCK. A truck with the body and engine mounted on the same chassis.

STRIP THE TRAILER. (Slang) Unload the trailer.

SURCHARGE. A charge in excess of what is usual or customary. It can apply to freight rates, fuel prices or fuel taxes, but usually is assumed to be temporary.

SUSPENSION. The system of springs, shocks, etc., supporting a vehicle upon its undercarriage or axles.

SWAMPER. (Slang) A helper who rides with the driver.


TANDEMS. The two drive axles on a tractor; also, one trailer directly behind the other and working together.

TRAC LEASE. Terminal Rental Adjustment Clause lease. A vehicle lease that enables the lessee to keep the vehicle at the end of the lease, provided he pays the lessor the vehicle’s residual value.

TRADE CYCLE. The length of time between purchase and trade of a truck or trailer, based on factors such as balance owed, equipment age, maintenance costs and repair history.

TRAFFIC. Department of a shipper responsible for coordinating the transportation of goods.

TRAILER ON FLATCAR (TOFC). Refers to piggyback intermodal operation of transporting trailers on railroad flatcars.

TRANSFER PUMP. A pump used to move fuel from fuel tank and injectors or carburetor.

TRANSMISSION. Selective gear box providing various combinations of gear ratios.

TRUCKLOAD. The maximum legal weight of a trailer; or, when used to describe freight rates, the minimum weight of a shipment necessary to qualify for the cheaper rate; or, a full trailer load shipment described by a single bill of lading. See LESS THAN TRUCKLOAD.

TURN. (Slang) A round-trip freight run.

U-BOLT. A somewhat horseshoe-shaped bolt, threaded on both ends, used to hold springs together in a spring suspension.

UNDER DISPATCH. Insurance term meaning an owner-operator is operating on instructions received by the carrier and therefore is covered by a carrier’s liability insurance. Whether an owner-operator was under dispatch at the time of an accident is of crucial importance in determining whether the carrier or the owner-operator is liable.

UNLADEN INSURANCE. Liability insurance that covers the owner-operator when he is pulling an empty trailer, regardless of dispatch status.

VALVE. A device that opens and closes openings in a pipe, tube or cylinder.

VARIABLE COSTS. Costs that vary by the number of miles run — for example, fuel, repairs and tolls. Sometimes called running costs. See FIXED COSTS.

VCR. Driver’s daily vehicle condition report.

VOLTAGE REGULATOR. A device that controls the voltage output of a generator.

WATER PUMP. Pump that circulates the coolant through the engine cooling system.

WHEELBASE. The distance in inches from the center of a truck’s front hub to the center of the space between its tandems.

WOODCHUCK. (Slang) Driver with low job priority.

YARDBIRD. (Slang) A driver who connects and disconnects tractor/semi-trailer combinations and moves vehicles around the terminal yard.