[A]
[B] [C] [D] [E]
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- I -
Independent Trucker
See
Owner Operator.
ITS (Intelligent Transportation Systems)
See
IVHS.
IVHS (Intelligent
Vehicle Highway Systems)
Blanket term for a wide array of technologies,
including electronic sensors, computer hardware
and software and radio communications. The purpose
of IVHS is to increase efficiency of use of
existing highways, reducing travel time, fuel
consumption, air pollution and accidents. There
are five functional areas:
o
Advanced Public Transportation Systems (APTS)
o
Advance Traffic Management Systems (ATMS)
o
Advance Traveler Information Systems (ATIS)
o
Advanced Vehicle Control Systems (AVCS)
o
Commercial Vehicle Operations (CVO)
A more recently coined term, Intelligent
Transportation Systems (ITS), encompasses both
IVHS and modes of transportation other than
highway, such as rail.
- J -
Jackknife
To place the trailer at a very sharp angle to the
tractor.
JIT (Just-In-Time)
Manufacturing system which depends on frequent,
small deliveries of parts and supplies to keep
on-site inventory to a minimum.
- K -
Kingpin (axle)
Pin around which a steer axle's wheels pivot.
Kingpin (trailer)
Anchor pin at the center of a semitrailer's upper
coupler which is captured by the locking jaws of a
tractor's fifth wheel to attach the tractor to the
semitrailer.
- L -
Landing Gear
Retracting legs which support the front of a
semitrailer when it is not coupled to a tractor.
LCV (Long Combination Vehicle)
In general, vehicles longer than a standard
doubles rig (tractor and two 28-foot semitrailers).
Examples of LCVs which are permitted in some U.S.
western states and eastern toll roads: Twin
48-foot trailers; triple 28-foot trailers.
Lessee
Company or individual which leases vehicles.
Lessor
Company which leases vehicles.
Lift Axle
Extra, unpowered axle needed only when the
vehicle is loaded, allowing it to meet federal and
state vehicle weight standards. The lift axle is
mounted to an air spring suspension that raises
the axle when it is not required.
LPG
Liquid propane gas.
Load Range (Tires)
Letter code system for the weight carrying
capacity of tires. Comparable ply ratings are
shown below.
LR PR LR PR
A
.... 2 E .... 10 B .... 4 F .... 12 C ....
6 G .... 14 D ....
8 H .... 16 (LR = Load Range PR = Ply
Rating)
Logbook
Book carried by truck drivers in which they
record their hours of service and duty status for
each 24-hour period. Required in interstate
commercial trucking by the U.S. Department of
Transportation.
Lowboy
Open flat-bed trailer with a deck height very low
to the ground, used to haul construction equipment
or bulky or heavy loads.
LTL (Less-Than-Truckload)
A quantity of freight less than that required for
the application of a 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.
- O -
Overdrive
Gearing in which less than one revolution of a
transmission's input shaft causes one turn of the
output shaft. The purpose of overdrive is to
reduce engine rpm in high gear for better fuel
economy. Example: A transmission with an overdrive
top gear has a ratio of 0.70 to one. Turning the
input shaft 0.7 revolutions causes 1.0 revolution
of the output shaft.
Owner-Operator
Trucker who owns and operates his own truck(s).
- P -
P&D
Pickup and delivery.
Payload
Weight of the cargo being hauled.
Peddle Run
Truck route with frequent delivery stops.
Pigtail
Cable used to transmit electrical power from the
tractor to the trailer. So named because it is
coiled like a pig's tail.
Piggyback
Semitrailer built with reinforcements to
withstand transport by a railroad flatcar.
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 drawbar eye of a trailer or
dolly.
Ply Rating (PR)
Relative measure of tire casing strength. (see
Load Range)
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 transportation. (see
For-Hire Carrier)
PSI (Pounds Per Square Inch)
In trucking, unit of measurement for tire air
pressure, air brake system pressure and
turbocharger boost.
PTO (Power Takeoff)
Device used to transmit engine power to auxiliary
equipment. A PTO often drives a hydraulic pump,
which can power a dump body, concrete mixer or
refuse packer. Some designs mount to a standard
opening on the transmission, while others attach
at the front or rear of the engine.
Pull Trailer
Short, full trailer (supported by axles front and
rear) with an extended tongue.
Pup Trailer
Short semitrailer, usually between 26 and 32 feet
long, with a single axle.
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