Trucking Industry Terminology: A Glossary of Terms

The trucking business has nearly as many industry-specific terms as the logistics and warehousing world. Fortunately, we’ve gathered a comprehensive list covering the most common and arcane terms in the trucking industry.


Agricultural Exemption: An exemption from route and rate regulation in motor carriage when the carrier is hauling basically raw/unprocessed agricultural products.

Air Ride Suspension: Suspension that supports the load on air-filled rubber bags rather than, or in conjunction with, steel springs. For a more comfortable and smoother ride.

Authorized Carrier: Person/company authorized by the U.S. Department of Transportation to engage in the transportation of property as a common or contract carrier.

Autonomous Vehicles: Self-driving vehicles, may be used in platooning situations.

Auxiliary Transmission: Secondary transmission that’s coupled with the primary transmission.

Axle Load: Weight existing on a motor vehicle’s axle. 2) A maximum allowable axle weight limit on a roadway or highway.

Axle Rating: The amount of carrying capacity as indicated by the axle manufacturer.


BHP: Brake Horsepower, engine horsepower rating as determined by brake dynamometer testing.

Backhaul: A load that returns the truck driver and/or the vehicle back to its homebase.

Bed Bugger: A truck that moves household goods from one point to another.

Berth: Sleeping compartment behind the cab.

Bill of Lading (BOL): A transportation document that is the contract of carriage containing the terms and conditions between the shipper and carrier.

Bill of Lading Number: The number assigned by the carrier to identify the bill of lading.

Bill of Material (BOM): A structured list of all the materials or parts and quantities needed to produce a particular finished product, assembly, subassembly, or manufactured part, whether purchased or not.

Binder: 1) Device used to apply tension to chains used to secure a load. 2) Slang term for brakes.

Blind side: Right side of a truck or combination unit that the driver cannot see without the use of mirrors.

Blocking: Pieces of wood or other material used to prevent movement of load in rail, vessel or truck shipments.

Bobtail: Tractor operating without a trailer. (Also a deadhead.)

Bogie: 1) An assembly of two or more axles. 2) Removable set of trailer axles and wheels.

Bonded Warehouse: A warehouse approved by the Treasury Department, used for storing goods until duties are paid or goods are otherwise properly released

Box: 1) Slang term for a van trailer. 2) Slang term for a transmission.

Brake Chamber: Air chamber mounted near each wheel and connected to the brake itself by a push rod and slack adjuster (cam brake) or a push rod (wedge brake).

Bulk Cargo: Unpacked dry cargo such as grain, iron ore or coal. Any commodity shipped in this way is said to be in bulk.

Bunk: Sleeping compartment behind the cab.


CDL: Commercial Driver’s License. Allows people to drive a truck or bus that weighs more than 26,001 pounds and is used in support of a business.

CPM: Cents per Mile. The per-mile rate at which drivers are paid.

Cabover: Cab-Over-Engine (COE). A type of truck design with the cab over the engine.

Cabotage: Point-to-point transportation of property or passengers.

Cargo: Goods or produce transported by ship, aircraft, or other intermodal vehicles such as trains, vans or trucks.

Cargo Control Number (CCN): Identifies both the carrier and shipment to the CBSA at the time of reporting and when release documents are presented.

Cargo Weight: The weight of the loads, gear and supplies on a vehicle.

Cartage Company: A company that provides local pickup and delivery.

Chassis Weight: The empty weight of a vehicle, without occupants or a load. Also curb weight and tare weight.

Chocks: Block or stop barriers placed behind/in front of wheels to keep vehicle from rolling. Also used on loads to prevent shifting.

Circus Wagon: Low sided trailer with high bow tarp.

Combination: Truck/truck-tractor coupled to one or more trailers, including semitrailers.

Commingling: Mixing types of goods from separate shipments and sending them as a combined shipment. Interstate and intrastate goods can move together in such a shipment.

Common Carrier: A company that will carry freight for any customer, as opposed to a private or dedicated carrier that only works for one customer.

Container: Shipping Container. One giant box, about 20 or 40 feet long that will fit in ships’ holds and can also be carried by rail or truck. Some containers are lighter and longer and are only used in rail and road transportation.

Container Chassis: A trailer designed to carry containers.

Contract Carrier: A company that carries freight for a small number of customers under contract.

Creeper Gear: Lowest gear/combination of gears on a tractor used when extra power is needed.


Deadhead: A truck with no cargo.

Dispatcher: The individual in charge of scheduling, driver communication, routes, and more.

Dispatching: The scheduling and control of truck pickup and delivery.

Double Clutch: Shifting the gears of a truck transmission without clashing them.

Doubles: A combination of a truck and two trailers.

Drayage: Carrying freight a short distance as part of a longer trip. For example, a tractor picking up freight from a rail yard and carrying it 50 miles to its final destination.

Drive Axles: Axles with powered wheels.

Drom Box: Unit mounted behind the cab of a truck-tractor capable of carrying freight.


EDI: Electronic Document Interchange. An electronic system for sharing transportation-related documents like bills of lading.

E-Log: A computerized system to keep track of their hours of service and miles. The carrier and dispatcher have instant access to this information, which improves their ability to schedule drivers appropriately. The federal government favors the use of E-Logs over traditional hand-written logs.

Exempt Carrier: Motor carrier engaged in for-hire transportation of commodities exempt from authority requirements of the FMCSA, generally unprocessed agricultural commodities or seafood.

Expediting: To accelerate transportation. Expedited freight service is usually faster than normal service. An example is dispatching less than truckload quantities, on a single truck, for quick delivery.


Federal Excise Tax: Commonly in trucking, tax paid on the purchase of a commercial vehicle and certain add-on components, such as tires

Federal Motor Carrier Association: (FMCSA) Division of the US Department of Transportation responsible for the implementation and enforcement of commercial motor vehicle safety regulations

Fifth Wheel: The way tractors and trailers are connected. The fifth wheel accepts a trailer’s kingpin and supports the front end the trailer.

Fleet Data Consolidation: A method of data analysis that helps fleets make more informed decisions.

Forced Dispatch: When the company dispatcher assigns a load, customer and delivery time to a driver and the driver must take the load or suffer consequences (such as being forced to wait around several hours or another day for another load, or even being fired).

Freight Carriers: Companies that haul freight, also called “for-hire” carriers. Methods of transportation include trucking, railroads, airlines, and seaborne shipping.

Freight Charge: The rate established for transporting freight.


Geared Speed: Calculated vehicle speed at the engine’s governed rpm in each transmission gear, or (commonly) in top gear.

Gear Ratio: Number, usually expressed as a decimal fraction, representing how many turns of the input shaft cause exactly one revolution of the output shaft. Applies to transmissions, power takeoffs, power dividers and rear axles.

Glad Hands: Air hose connectors between tractor and trailer.

Governor: A device that regulates the truck’s top speed. Large fleets use these to ensure their drivers stay within guidelines to improve fuel efficiency and safety.

Grade: The steepness of a hill. A 5% grade means a hill rises 5 feet per 100.


Headache Rack: A barrier behind the truck cab designed to protect the driver from behind in the case of a load shifting forward from the trailer.

Hot Load: Rush shipment of cargo.

Hours-Of-Service: FMCSA safety regulations governing how long and when drivers may be on duty and driving.


Icing Charge: A charge made for cooling perishable freight.

Indivisible Load: Any vehicle or load which cannot be dismantled, disassembled, or loaded to meet specific regulatory limits for size and/or weight.

Irregular Route Carrier: Common carrier authorized to haul to points in given area but not always on same route/schedule.


Jackknife: When the tractor and trailer are at a sharp angle to one another.

Jake Brake: The Jacobs Engine Brake is a compression release engine brake, often called a “Jake brake,” which allows a truck driver to use exhaust back pressure by opening the exhaust valves in the cylinders following the compression cycle, thereby slowing the truck. The Jake brake essentially increases the truck’s braking power, which is beneficial when traveling downhill.


Kingpin (axle): An axle’s wheels pivot around a kingpin.

Kingpin (trailer): Connects the truck to trailer.


LTL: Less-Than-Truckload. Carrying less cargo than a full truckload weight for a customer. This includes shipping one package or half of a truckload.

LTL Carrier: A company that specializes in combining smaller shipments for multiple customers on one truck.

Landing Gear: Supports to hold up the front end of a trailer when it is not attached to a tractor.

Lessee: A company or person that pays money to use someone else’s property.

Lessor: A company or person that owns the property someone else is paying to use.

Lift Axle: An extra axle that can be lowered and put into use for a heavier load so that the vehicle can meet federal and local weight standards.

Logbook: A truck driver’s book for recording hours and activities during a 24-hour period.

Logistics: The art and science of getting people and materials where they need to be when they need to be there.

Long-haul: Driving long distances.

Lumper: Person hired on site to unload cargo; casual labor.


Mixed Truckload: A truckload of different articles combined into a single shipment.


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


OTR: Over-the-Road. Long-haul trucking, as opposed to local or regional.

Operational Records: Documents supporting miles traveled in each jurisdiction and total miles traveled such as fuel reports, trip sheets, logs or computer runs that can be supported by source documents when requested by the base jurisdiction.

Overage: Excess freight over the quantity believed to have been shipped, or more than the quantity shown on a shipping document.

Owner-Operator: Trucker who owns or leases and operates his own truck(s).


PTDI: Professional Truck Driver Institute. This organization certifies truck driver training programs. It does not teach CDL classes.

Pancake: Brake diaphragm housing

Payload: Weight of the cargo being hauled.

Peddle Run: Truck route with frequent delivery stops.

Perishable Freight: Freight subject to decay or deterioration.

Pig: Trailer transported on a railcar.

Pigtail: Cable used to transmit electrical power from the tractor to the trailer.

Platooning: Grouping vehicles into platoons to increase capacity and efficiency.

Point of Origin: The location at which freight is received from the shipper.

Power Brake: Accelerate while applying the brakes.

Private Carrier: A fleet that specializes in carrying goods for its own company.

Pull the Pin: Release the fifth wheel lock.

Pusher axles: Unpowered and go ahead of drive axles.

Put on the Air: Apply the brakes.


Qualcomm: A wireless communication system that carriers use to keep in touch with drivers. It’s like a combination of GPS, email and text messaging. The system helps the company keep track of its trucks and it helps drivers know the status of their next load and the weather.


Rear axles: May be drive, tag or pusher types.

Reefer: Refrigerated truck or trailer designed for hauling perishables.

Regular Common Carrier: Any company authorized to serve the public and to transport general commodities over set routes.

Regular Route Common Carrier: Motor carrier operating over definite routes between specified points with fixed terminal on regular schedule.

Relay: Two drivers start out in two different origin points several hours apart with loaded trucks. They meet in the middle, exchange cargo and return to their points of origin.

Rig: Truck; tractor-semitrailer; truck and full trailer, or other combination.

RoadRailer: A trailer made to travel on both road and rail.

Runaway Ramp: Often seen on a steep grade, these are wide, soft areas a truck can pull into to slow down when its brakes lose power.


Saddle Tank: Fuel storage area on a tractor.

Safety Bonus: A benefit offered by some trucking companies to reward safe drivers.

Semi: Semitrailer; used loosely in referring to tractor and semitrailer combination.
Shipping Weight: The weight of a truck not including the liquids like fuel and coolant.

Sleeper: A space to sleep behind the truck’s cab.

Sleeper Team: When two drivers work together so one can sleep while the other one drives, allowing freight to move as fast as possible while staying within federal hours of service regulations.

Sliding Fifth Wheel: A fifth wheel that can move back and forth to change weight distribution among axles.

Slip-Seat: Relay operation where drivers are changed periodically, but the truck continues from origin to destination.

Smart Drive Cameras: Video and analytics technology that improve visibility, increase documentation, and promote safety.

Straight Truck: A one-piece truck with the cargo area attached to the chassis, as opposed to a tractor-trailer combination vehicle.

Synchronized Transmission: Transmission with built-in mechanisms to automatically “equalize” the speed of its gears to allow smooth shifting without the need to double clutch.


TL: Truckload. A full trailer-load of freight.

TL Carrier: A trucking company that carries a single shipper’s freight on one truckload.

Tractor: A truck that is made to pull a trailer.

Tachograph: Also, “tattle-tale” — A device used in a cab to automatically record miles driven, number of stops, speed, and other factors during a trip.

Tag axles: Unpowered and go behind drive axles.

Tractor Trailer: A truck and trailer together.

Transfer Company: A firm that specializes in handling cross-border transactions.

Transponder: An electronic tag mounted in a motor vehicle that contains electronically stored information that can be retrieved by a roadside reader.


Weigh Station: Permanent station equipped with scales at which motor vehicles transporting property on public highways are required to stop for checking of gross vehicle and/or axle weights; many states also use portable scales to check compliance with the State’s weight limits; also often combined with port of entry facilities.


Yard Tractor: A tractor that moves trailers around a warehouse or distribution center.

Sources: Trucking Job Finder,, OOIDA Foundation, IRPonline, Wikipedia