Cabover (Cab-Over-Engine, COE) Truck or tractor design in which the cab sits over the engine on the chassis.

Cargo Weight Combined weight of all loads, gear and supplies on a vehicle.

Cartage Company Company that provides local (within a town, city or municipality) pick-up and delivery.

Cast Spoke Wheel Wheel with five or six spokes originating from a center hub. The spoked portion, usually made of cast steel, is bolted to a multiple piece steel rim.

CB (Citizens Band Radio) Two-way radio for which no license is required by the Federal Communications Commission (FCC). Long beyond its heyday in the '70s, CB is still used by truckers and motorists for everything from traffic condition reports to emergency calls to idle chatter. 

CDL (Commercial Driver's License) License which authorizes an individual to operate commercial motor vehicles and buses over 26,000 pounds gross vehicle weight. For operators of freight hauling trucks, the maximum size which may be driven without a CDL is Class 6 (maximum 26,000 pounds gross vehicle weight).

CE (CF, LP) Distance from back of a truck's cab to the end of its frame.

CG (Center of Gravity) Weight center or balance point of an object, such as a truck body. Calculated to help determine optimum placement of truck bodies on chassis.

Chassis Weight (Curb Weight, Tare Weight) Weight of the empty truck, without occupants or load.

Clearance  Lights The lights that are on top of the Front and rea of the Semi-trailer.

CNG Compressed natural gas.

COFC (Container On Flat Car) Method of moving shipping containers which involves transporting them on railroad flat cars.

Common Carrier Freight transportation company which serves the general public. May be regular route service (over designated highways on a regular basis) or irregular route (between various points on an unscheduled basis).

Compensated Intracorporate Hauling Freight transportation service provided by one company for a sister company.

Container (Shipping Container) Standard sized rectangular box used to transport freight by ship, rail and highway. International shipping containers are 20 or 40 feet long, conform to International Standards Organization (ISO) standards and are designed to fit in ships' holds. Containers are transported on public roads atop a container chassis towed by a tractor. Domestic containers, up to 53 feet long and of lighter construction, are designed for rail and highway use only.

Consignee The receiver. The company taking in your freight. The place you deliver your load to.

Container Chassis Single purpose semi-trailer designed to carry a shipping container.

Contract Carrier Company that transports freight under contract with one or a limited number of shippers.

Conventional A style of truck with the engine compartment located in front of the cab or driver’s compartment.

Conventional spring system A system which uses the conventional front and rear suspension springs.

Converter Dolly (Dolly) Auxiliary axle assembly equipped with a fifth wheel (coupling device), towed by a semi-trailer and supporting the front of, and towing, another semi-trailer.

Cube (Cubic Capacity) Interior volume of a truck body, semi-trailer or trailer, measured in cubic feet.