A
weigh station is a checkpoint along a highway to
inspect vehicular weights. Usually,
trucks and
commercial vehicles are subject
to the inspection.
Overview
Weigh stations are equipped with
scale, some of which permit the trucks to
continue moving while being weighed, while older scales require the
trucks to stop. There are a variety of scales employed from single
axle scales to multi-axle sets. Signal lights indicate if the
driver should pull over for additional inspection or if they are
allowed to return to the highway.
Some jurisdictions employ the use of portable scales, allowing
weigh stations to be set up at any point. Portable scales allow
states to set up temporary scales for situations such as seasonal
check points, temporary checkpoints on isolated roads often used by
trucks, and help prevent drivers from avoiding scales at fixed
locations. Portable scales may be set up at purpose built locations
that are not normally manned. A common reason for setting up
portable scales is to monitor trucks during harvest season.
United States
A weigh station located near state border is called a port of
entry. States may also locate weigh stations in the interior of the
state. Interior weigh stations are often located at choke points or
areas where freight originates or is delivered.
Weigh stations were primarily created to collect road use taxes
before
IFTA created an integrated system of
doing so. While taxes can still be paid at weigh stations, their
primary function is now enforcement of tax and safety regulations.
These include: to check freight carrier compliance with
fuel tax laws; to check weight restrictions; to
check equipment safety; to check compliance with Hours of Service
Regulations. Weigh stations are regulated by individual state
governments and therefore have vastly different requirements from
state to state. They are typically operated by the state's
Department of Transportation
(DOT) or
Department of
Motor Vehicles (DMV) in conjunction with the state
highway patrol or
state police, thus enabling enforcement of
applicable laws. The federal maximum weight is set at 80,000
pounds. Trucks exceeding the federal
weight limit can still operate on the country's highways with an
overweight permit, but such permits are only issued before the
scheduled trip and expire at the end of the trip. Overweight
permits are only issued for loads that cannot be broken down to
smaller shipments that fall below the federal weight limit, and
there is no other alternative to moving the cargo by truck.
Permitted oversize trucks are often required to coordinate with the
Departments of Transportation and law enforcement agencies of the
transited states before the trip begins, as most states require
oversize trucks to be
escorted. Many
states have weigh-in-motion technology that allow a continuous flow
of truck weighing.
Many states also check freight paperwork, vehicle paperwork, and
logbooks to ensure that fuel taxes have been paid and that truck
drivers are obeying the
Hours of
Service (a federal requirement). Also the truck and driver may
have to undergo a
DOT inspection as most states perform the bulk
of their DOT inspections at their weigh stations. In some cases, if
a truck is found to be overweight, the vehicle is ordered to stop
until the situation can be fixed by acquiring an overweight permit.
In other cases, the driver may receive an overweight ticket and may
or may not be required to offload the extra freight. Offloading the
extra freight may not be practical for perishable or hazardous
loads.
The
first state to implement a weight law was Maine
, which set a
limit of 18,000 pounds (8 tons; 8,200
kg) in 1918.
Two types of loads may result in overweight trucks. Divisible and
non-divisible. A divisible load is a load which can be easily
divided into smaller parts- like products that are shipped on
pallets or automobiles or grains, etc. A non-divisible load is a
load which is unable to be divided into smaller parts- like a piece
of equipment or a steel beam. All states provide permits for
non-divisible loads though the truck may have restricted routing.
Some states allow tolerances for any over weight truck. Some states
have specific allowances for types of loads for which they will
allow tolerances. For example, Wyoming allows 2000 pounds for
chains, tarps and donnage that accompany a non-divisible load
[245355].
Truckers often refer to weigh stations as "chicken coops."
[245356]The song '
Convoy' by C W McCall refers to the
aforementioned 'chicken coops' in the line:"Those chicken coops
were full of bears and choppers filled the skies"
Electronic Weigh Station Bypass
Many states now use electronic bypass systems to alleviate some of
the truck traffic through the weigh station.
It is best known as
PrePass, NorPass in Kentucky
, or simply
A.V.I. (Automatic Vehicle Identification). The system
consists of the equipment at the weigh station itself, as well as a
truck mounted transponder, usually placed on the inside of the
windshield. These are similar to transponders used for
toll collection. Each transponder is directly
registered to a specific truck, and contains a unique
identification. The registration process propagates information
such as carrier name, unit number, and elected gross weight to
weigh stations. In addition, the system keeps a basic safety and
compliance record for each vehicle. As a truck approaches a weigh
station (approximately one mile before), an electronic "reader" on
a boom over the freeway reads the information from the truck
transponder. At the same time, the truck is usually driving over
high-speed electronic scales embedded in the road. The system
computes the weight, by axle and gross, and determines if it is
within the limits. It also looks at the
safety and compliance record on
the data base. The A display shows the results to the weigh master,
including the speed of the vehicle. The weigh master may have the
system automatically determine if a truck needs to stop or may
override the system. Approximately one-half to one full mile after
passing under the "reader", the truck will pass under another boom
which has an electronic unit to send the transponder a signal. If
the weight and safety information are acceptable the truck may
receive a green light and can continue without entering the weigh
station at all. A driver may get a red light. On these occasions,
the truck must pull into the weigh station for the normal weigh-in
procedure. The most common reason a truck is "redlighted" is a
weight problem, or a random check. Each time a truck is randomly
pulled in, it is noted in the system whether the driver was
compliant or not during the check. This affects how often a truck
(or different trucks from the same company) are pulled in. For
example, a company who is very compliant with the law, will
probably only have 5% of its trucks "redlighted." On the other
hand, a company whose trucks have compliance issues during the
random checks will have their information updated accordingly, and
might get "redlighted", for example, 30% of the time.
In popular culture
In the film
Super Troopers,
officers Mac and Foster stop a semi marked with Bunty soap after if
failed to stop at a weigh station.
In
Knight
Rider Season 2 episode "Mouth of the Snake", originally
aired on April 8, 1984, a highway patrol officer tries to stop a
tractor-trailer failing to stop at a
weigh station, only to find a
rocket fired
from the trailer to kill him to evade law enforcement.
In the first season
CHiPs episode
"Aweigh We Go," Ponch and Jon are assigned a week's investigative
duty at a weigh station to investigate a series of tractor-trailer
thefts.
In the film
Black Dog, the
main character Jack Crews (
Patrick
Swayze) is a truck driver transporting illegal weapons and is
nearly caught when he stops at a weigh station on the
highway.
Canada
British Columbia
Weigh Stations (aka "Scales") are usually on the right-hand side of
the travelled highway, but median scales are appearing (as of 2005)
on divided highways, often combined with "weigh-in-motion"
technology.
A median scale is placed between the opposing lanes of traffic,
necessitating heavy vehicles exiting from the left lane (rather
than the right) and re-entering traffic from the left, potentially
at a lower speed than the normal "free-flow" traffic would expect
in the left (often thought of as "fast") lane.
"Weigh-in-motion" technology allows heavy vehicles that do not
exceed limits of weight (and size) to pass the scale, thus
improving both freight and weigh scale operation efficiency.
Alberta
In Alberta, scales can be on either side of the road, on the median
or off-highway. Flashing lights inform drivers as to whether the
scale is operational. Occasionally, the lights may be operational
in only one direction.
Alberta scales are all of the 'weigh-in-motion' type, and vehicles
are not required to stop; they merely have to slow to 10
km/h.
Scales which are not operational are often available to drivers as
a 'self-weigh' site, where drivers can check their axle loads
without enforcement officials being involved.
North West Territories
The government of the North West Territories operates only one
scale. It is situated in the townsite of Enterprise, 83 kilometres
north of the border with Alberta, and issues permits for vehicles
from other jurisdictions as well as weighing vehicles and enforcing
hours of service legislation.
Taiwan

A Weigh Station Sign in Taiwan with
the Chinese text reading: trucks are to be weighed
In Taiwan, weigh stations ( ) are located on major highways,
especially at all
toll booths on
freeways. Advanced signs tell that trucks
must enter the weigh stations when the attached lights are
flashing, usually when tolls are collected.
Since the
National
Highway No. 1
was built with older designs, all weigh stations have older scales
so trucks must stop. Weigh stations along the
National Highway No.
3 have weigh-in-motion
scales at 7 central and southern toll stations, but northern
stations at Cidu, Shulin
, and
Longtan have traditional scales where trucks
must stop.
The Taiwan Area National Freeway Bureau applies for periodical
inspections of truck scales every three months. Truckers entering a
weigh-in-motion scale are advised not to accelerate or decelerate
suddenly, or they may be required to be weighed again.
References
External links