Weigh station
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A weigh station is a checkpoint along a highway to inspect vehicular weights. Usually, trucks and commercial vehicles are subject to the inspection.
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[edit] Overview
Weigh stations are equipped with scales, 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 help prevent unscrupulous drivers from circumventing the law by avoiding scales at fixed locations.
[edit] United States
Weigh stations are located within states near the borders of other states, and also commonly along highways in the state. The purpose is to check freight carrier compliance with fuel tax laws and weight restrictions. 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) in conjunction with the state highway patrol or state police, thus enabling enforcement of applicable laws. 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). In some cases, if 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.
Truckers often refer to weigh stations as "chicken coops."
[edit] 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, Advantage 75 in Georgia, 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 information such as carrier name, unit number, and elected gross weight. 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 transponder. 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 will 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.
[edit] In popular culture
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.
[edit] Canada
[edit] 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.
[edit] Taiwan
In Taiwan administered by the Republic of China, weigh stations (Traditional Chinese: 地磅站) 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 that trucks must stop.
The Taiwan Area National Freeway Bureau applies for periodical inspections of truck scales every three months.[1] Truckers entering a weigh-in-motion scale are advised not to accelerate or decelerate suddenly, or they may be required to be weighed again.[2]
[edit] References
- ^ Taiwan Area National Freeway Bureau: Frequently asked questions (Chinese)
- ^ Taiwan Area National Freeway Bureau: Safe Driving Guide (Chinese)
[edit] External links
