Glossary of Trucking Terms

ABS (Anti-lock Braking System) – Computer,
sensors and solenoid valves which together
monitor wheel speed and modulate braking force
if wheel lockup is sensed during braking. Helps
the driver retain control of the vehicle during
heavy braking on slippery roads.

Air Ride Suspension – Suspension which supports
the load on air-filled rubber bags rather than steel
springs. Compressed air is supplied by the same
engine-driven air compressor and reservoir tanks
which provide air to the air brake system.

Anchor It – Apply brakes for an emergency stop.

Bill of Lading – Itemized list of goods contained in
a shipment.

Blind Spot – Areas around a commercial vehicle
that are not visible to the driver either through the
windshield, side windows or mirrors.

Bobtail –Tractor operating without a trailer. Also
refers to a straight truck.

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.

CDL (Commercial Driver’s License) – License
which authorizes an individual to operate
commercial motor vehicles and buses over 26,000
pounds gross vehicle weight.

Container – Standard-sized rectangular box used
to transport freight by ship, rail, and highway.

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

Doubles (Twins, Twin Trailers) – Combination of a
tractor and two semitrailers connected in tandem
by a converter dolly.

EOBR (Electric On-Board Recorder) – Cab-mounted
device which electronically records data such as
truck speed, engine rpm, idle time and other
information useful to trucking management.

Exempt Carrier – Company which transports
commodities exempted from Interstate
Commerce Commission economic regulation.

For-Hire Carrier – Company in the business of
transporting freight belonging to others.

Hazmat – Hazardous materials, as classified by
the U.S. Environmental Protection Agency.

Transport of hazardous materials is strictly
regulated by the U.S. Department of Transportation.

Hours-of-Service – U.S. Department of
Transportation safety regulations which govern
the hours of service of commercial vehicle drivers
engaged in interstate trucking operations.

Intermodal Transportation –The transportation
movement involving more than one mode (e.g.,
rail/motor, motor/air, rail/water).

JIT (Just-In-Time) – Manufacturing system which
depends on frequent, small deliveries of parts and
supplies to keep on-site inventory to a minimum.

Landing Gear – Retractable legs which support the
front of a semitrailer when it’s not coupled to a

LCV (Long Combination Vehicle) – In general,
vehicles longer than a standard doubles rig.

Examples of LCVs which are permitted in some
U.S. western states and eastern toll roads: Twin
48-foot trailers; triple 28-foot trailers.

Logbook – Book carried by truck drivers in which
they record their hours of service and duty status
for each 24-hour period. Required for interstate
commercial trucking by the U.S. Department of

Line-haul Driver –Truck driver who travels a
set route from city to city and typically returns
home after each shift. Also known as a
regional driver.

Local Driver –Truck driver who picks up and
delivers packages along a city route. Drivers
typically run the same route every day, returning
home after each shift. Also known as a city
or P&D driver.

LTL (Less-Than-Truckload) – A quantity of freight
less than that required for the application of
truckload (TL) rate; usually
less than 10,000 pounds.

LTL Carrier –Trucking company which consolidates
less-than-truckload cargo for multiple destinations
on one vehicle.

Owner-Operator –Truck driver who owns and
operates his own truck.

Over-the-Road Driver –Truck driver who travels
cross-country to deliver freight and usually sleeps
within a berth in the truck cab. Typically averages
over 100,000 miles per year.

P&D – Pickup and delivery. May also be referred
to as a city driver.

Payload – Weight of the cargo being hauled.

Peddle Run –Truck route with frequent
delivery stops.

Private Carrier – Business which operates trucks
primarily for the purpose of transporting its own
products and raw materials.The principle
business activity of a private carrier is not

Professional Truck Driver – Different categories of
drivers include over-the-road, line-haul and local.

Reefer – Refrigerated trailer with insulated walls
and a self-powered refrigeration unit. Most
commonly used for transporting food.

Semitrailer –Truck trailer supported at the rear by
its own wheels and at the front by a fifth wheel
mounted to a tractor or a dolly.

Sleeper – Sleeping compartment mounted behind
a truck cab, sometimes attached to the cab or even
designed to be an integral part of it.

Sliding Fifth Wheel – Fifth wheel mounted to
a mechanism that allows it to be moved back and
forth for the purpose of adjusting the distribution
of weight on the tractor’s axles.

Straight Truck – Vehicle which carries cargo in a
body mounted to its chassis, rather than on a
the trailer towed by a vehicle.

TL (Truckload) –The quantity of freight required to
fill a trailer; usually more than 10,000 pounds.

TL Carrier –Trucking company which dedicates
trailers to a single shipper’s cargo, as opposed to
an LTL (less than truckload) carrier which
transports the consolidated cargo of several
shippers and makes multiple deliveries.

Tractor –Truck designed primarily to pull a
semitrailer by means of a fifth wheel mounted
over the rear axle.

Tractor Trailer –Tractor and semitrailer

Tri-Axle –Truck, tractor or trailer with three axles
grouped together at the rear.

Trip Leasing – Leasing a company’s vehicle to
another transportation provider for a single trip.