Weigh Stations: What Are They And How Do They Work?

September 28, 2021


You've probably noticed signs bearing "weigh station" by the highway and have had no clue what goes in there if you don't drive trucks or heavy vehicles. But truck drivers know these places too well.

A weigh station is an area for the inspection of trucks and other commercial vehicles. From the station's name itself, this is where the vehicles are weighed to ensure they do not go over the weight limit.

In fact, they call weigh stations "chicken coops" for reasons you'll get to understand soon.

In addition to the beautiful name these places have earned from truck drivers, you'll also learn what weigh stations are, what goes on in there, and how they work.


What is a Weigh Station?

A weigh station is a location off the highway where trucks and commercial vehicles go to measure their weights and get inspected by officials. These officials are often from the Department of Transportation, Department of Motor Vehicles, and Highway Patrols.

At the weigh stations, trucks get to weigh in motion on truck scales equipped to make it stop. Vehicles found to be overweight receive penalties accordingly. 

A weigh station on the border between states is known as a port of entry.

Because large vehicles are forced into a confined space prior to being weighed, weigh stations are also called “chicken coops”.

Tank Truck is Weighed on a highway scale

Why Should You Weigh Your Truck at the Weigh Stations?

It is important to subject your truck to inspection at the weigh station to protect your truck and trailer. It also serves as a safety measure for you as a truck driver and protects other people from accidents caused by overweight trucks.

Overweight vehicles can wreak untold havoc on the road. Examples of the dangers of overweight vehicles include:

  • tire blowouts
  • an increased velocity as the truck goes downhill.
  • difficult truck control
  • lengthy stop time after the brake is applied
  • rollovers

Truck rollovers are especially dangerous because they often lead to very devastating accidents on the road.

In addition to those dangers, overweight vehicles could compromise bridges and damage roads. This then increases the amount the government spends on repairing and maintaining roads. And no, the government doesn't like this. So they'll penalize whoever is found guilty of it.


3 Types of Truck Measurement Systems

Truck scales are the equipment with which trucks are measured at weigh stations. Their working mechanism includes the use of electric currents to measure weights. 

Truck scales come in 3 common types:

1. Load cell systems

Load cell truck scales are made of concrete or steel with an electric wire as a sensitized strain gauge. When the truck's weight compresses the electric wire, it sends the electric current to a junction box. It is in this junction box that the current gets measured and mapped to an appropriate weight.

2. Piezoelectric

Piezoelectric truck scales make use of sensors installed in conductive materials to measure truck weights. Under the truck scale, an electric current is sent from the conductive material to the sensors, where the weight is determined.

3. Bending Plates

The bending plate truck scale makes use of metal plates with strain gauges in them. During compression, the strain gauges send electric current to the junction box, which measures the electric current and apportions an equivalent weight to the truck. 

Depending on the technology age, truck scales measure weights with varying levels of efficiency. One-axle truck scales, for instance, require that the truck stops for measurement each time the wheel is positioned on the scale.

This can be a really slow process when the truck has a very long trailer. Another kind is the one-stop truck scale that is arranged in such a way that the total weight of the truck is measured once the truck stops on the scale.

Although the one-stop truck scale is an upgrade from the one-axle truck scale, it is still slow compared to a weigh-in-motion truck scale that works just as its name describes, making the weighing process faster. There are even new generation weigh-in-motion scales that weigh vehicles at highway speeds.


What Happens At Weigh Station Inspections?

While the truck is being weighed, inspections are ongoing by the officials at the stations. The inspection levels are divided into 6.

Inspection Level 1 and 2

This inspection is the standard inspection which covers basic truck and driver inspections. The inspectors check the necessary paperwork, including Hours of Service log, License, and Driver and Vehicle Inspection Report (DVIR). On the driver, the inspectors search for traces of drugs or alcohol. And on the truck, things like seatbelts, brakes, frames, electrical cables, coupling devices, and many more are checked.

Inspection Level 3

Level 3 inspection is a thorough inspection of the driver of the truck. This is where the inspectors check the driver's credentials and other items. Examples include:

  • Medical card waiver
  • HAZMAT requirements
  • Seat belt, Record of Duty Status (RODS)
  • Driver's license,
  • Drug and/or alcohol use, and many more.

Inspection Level 4 

The level four inspection focuses on specific aspects of the vehicle. The aspect is determined by the DOT.

Inspection Level 5 

The level five inspection is done on a truck after an accident or after the driver has been arrested for reasons pertaining to the truck. The driver isn't there while the inspection is ongoing, and it is very thorough.

Inspection Level 6 

The level six inspection is reserved for vehicles that carry Highway Route Controlled Quantities (HECQ) or radioactive materials. This inspection consists of processes from inspection level 1 but with additional checks of enhanced out-of-service criteria, radiological requirements, and radiological shipments.

Vehicles that fail to pass these inspections will risk having the Federal Motor Carrier Safety Administration (FMCSA) declaring them out-of-service. Mandatory repairs would be imposed on these vehicles, after which the FMCSA does another inspection to ensure that the truck is road-worthy once again.


What Trucks are to Stop at Weigh Stations?

The weight requirement is often different for every state. In most states, every commercial motor vehicle (CMV) with gross combination weight ratings of over 10,000 liable must always report to the weigh station. However, it’s 26,000 lbs for the state of Colorado and 8000 lbs for the state of Montana. To be sure, check the requirements of your state. 

The table below shows the weight requirement for each state:

State

Weight Guidelines

Arkansas

All vehicles above 10,000 lbs 

Alabama

Trucks above 10,000 lbs

Alaska

Trucks above 10,000 lbs

Arizona

Trailers and semi-trailers above 10,000lbs, commercial motor vehicles excluding school buses, agricultural vehicles, commodity, and dangerous chemicals and materials shipping vehicles. 

Colorado

Every vehicle beyond 26,000 lbs is to get clearance at the port of entry or the Colorado state patrol officer or Colorado Department of Revenue.

California

Trucks and commercial vehicles

Connecticut

All vehicles

Delaware

No vehicle must exceed 22,400 lbs single axle load

Florida

Vehicles carrying production, manufacture, sale, agricultural, livestock, storage, horticultural, travel, and camping products. Passenger vehicles weighing over 10,000 lbs or carrying over 10 passengers. Vehicles carrying HAZMAT.

Georgia

All vehicles above 10,000 lbs 

Hawaii

Trucks above 10,000 lbs

Illinois

Police officers choose based on suspicion.

Idaho

All commercial vehicles and trucks.

Indiana

Trucks above 10,000 lbs

Iowa

All vehicles above 10,000 lbs. 

Kansas

Police officers choose based on suspicion.

Kentucky

Commercial and agricultural vehicles above 10,000 lbs

Louisiana

Commercial vehicles above 10,000 lbs, agricultural vehicles, specialty vehicles with or without trailers, and passenger vehicles

Maryland

Commercial and agricultural vehicles above 10,000lbs, HAZMAT vehicles, and commercial vehicles with over 16 passengers.

Massachusetts

Commercial vehicles above 10,000 lbs, agricultural vehicles specialty vehicles with or without trailers, and passenger vehicles

Maine

Police officers choose based on suspicion.

Michigan

Dual rear wheel agricultural vehicles, trucks, tractors, and semi-trailers over 10,000 lbs

Minnesota

All vehicles above 10,000 lbs 

Mississippi

Police officers choose based on suspicion.

Montana

All vehicles above 8,000 lbs 

Missouri

Commercial trucks above 18,000 lbs

Nebraska

All trucks above 2,000 lbs excluding private RVs and recreational trailers

Nevada

Commercial and agricultural vehicles above 10,000 lbs

New York

Police officers choose based on suspicion.

New Hampshire

Police officers choose based on suspicion.

New Jersey

All vehicles above 10,000 lbs 

New Mexico

Trucks above 10,000 lbs

North Carolina

Officers choose based on suspicion.

North Dakota

All vehicles above 10,000 lbs 

Ohio

Commercial vehicles above 10,000 lbs

Oregon

All vehicles above 26,000 lbs 

Oklahoma

Police or Peace Officers choose based on suspicion.

Pennsylvania

Commercial vehicles, trucks, agricultural vehicles, large RVs, vehicles with large trailers

Rhode Island

Trucks above 10,000 lbs

South Dakota

Trucks and agricultural vehicles over 8,000 lbs

South Carolina

Officers choose based on suspicion.

Tennessee

Peace officers choose based on suspicion.

Utah

Police officers choose based on suspicion.

Vermont

Police officers choose based on suspicion.

Virginia

Trucks above 7,500 lbs

West Virginia

Police officers choose based on suspicion.

Washington

Agricultural vehicles above 10,000 lbs

Wyoming

Police officers choose based on suspicion.

Wisconsin

Trucks above 10,000 lbs

There are well over a million heavy-duty trucks roaming the highways of the United States. Only CMVs with weigh station bypasses may not use the weigh stations. But not many of them have this prepass. This still leaves many CMVs to visit the weigh stations, causing them to be congested with long truck queues slowly proceeding to the weighing and inspection points. It is no wonder truck drivers refer to weigh stations as chicken coops.


Do trucks have to stop at every weigh station?

You may now be wondering, “what if there’s more than one truck weigh station on your route. Do I have to stop at every one of them?” 

You have to stop at every weigh station you come across. It’s the law to stop at as many weigh stations as you come across as long as they are open.

Truck Scale Reading

What happens if a truck doesn’t stop at a weigh station?

Failing to stop at an open weigh station could attract fines from $300 upward. Your license may also be suspended by the DOT. And don’t ever imagine you can always skip weigh stations. You might get away with it once or twice, but when you are caught, the consequences are grievous.


What happens to overweight trucks at weigh stations?

Consequences for overweight trucks vary from state to state but generally revolve around:

Fines

Fines can be as high as $10,000 and multiple offenders may have to pay double or triple the normal fine.

Delay of Service

Overweight trucks could be delayed, which is a severe punishment in a trucking business. It may hurt a company’s reputation and customer relationships.

Jail

Jailing the truck driver is another way some states deal with overweight trucks. The sentence could last for up to 2 months, accompanied by the revoking of the driver’s CDL.


How to avoid weigh stations

You can still avoid weigh stations legally, however, through any of these ways:

  1. Taking another route that has no weigh stations. There are smartphone apps that help you plan your route on various app stores.
  2. Waiting until the weigh station closes. Some smartphone apps also have this feature too.
  3. Getting a weigh station bypass

Summary

Weigh stations may sometimes seem like they’re evil, but they are necessary. They help keep the world safe, and you should play your part too. Pull into any open weigh station you come across, and try not to load your truck beyond the weight threshold. 

Also, be sure to always check the road rules of your state to know what rules apply to your truck and if you need to stop at weigh stations along the way. 

About the author

I’m Luis Uribe, author of this website. I am the owner and head publisher for Trucker Daily and a freight brokerage Total Connection Logistics. I have been in and around the trucking industry for over 15 years. It is my mission with Trucker daily to equip truck drivers, with the latest in industry updates, news, and helpful tips to help further your trucking career and life. Whether you are a truck driving veteran, or beginner, you will find information on this site to save you a lot of time in your driving journey.

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