Why Do We Have Truck Weigh Stations?

Driving along an interstate highway, you may have noticed signs for truck scales, or perhaps you’ve seen trucks at these stations and wondered what was going on, or if you could use those scales yourself. Whatever state you find yourself in the United States, you can find versions of these weigh stations that are permanent fixtures of the road (other than Massachusetts and New York, which only use temporary weigh stations).

You might find them at choke points, or see new stations crop up on roads that some truckers have started using to avoid the permanent weigh stations. In the continental U.S., you will certainly come across weigh stations at state borders. In total, there are several hundred weigh stations in use throughout the country at any given time, most of which are permanent, many of which are found on major highways.

They pop up everywhere, and they are mandatory for many truck drivers to use, but why do they matter? The answers can vary as you cross state lines, but across the board, weigh stations are meant to ensure that trucks aren’t dangerously overloaded. Otherwise, these vehicles are a serious danger for the roads themselves, for the truck drivers, and of course, to anyone who shares the road with them.

What Vehicles Are Weigh Stations For?

Weigh stations are for commercial vehicles. This can include certain buses and other commercial motor vehicles, but what you will usually see are tractor-trailers, tanker trucks, and other trucks like these at weigh stations. Specifically, weigh stations are for commercial vehicles that weigh more than 10,000 pounds. For reference, passenger cars often weigh 4,000 pounds, while some larger personal-use trucks can weigh up to 8,000 pounds.

What if you’re driving an RV, could you drive through for fun, just to check out the result? No, most personal-use RVs don’t weigh enough to cross the weight threshold for these stations, and these weigh stations are not to be used out of curiosity. What if the RV is for business? Then that depends on the state.

If an RV is being used for business and weighs around 10,000 pounds, it might have to stop at weigh stations in:

What Are Truck Weigh Stations For?

Much of this article will go on to discuss the steps involved in weighing and inspecting a commercial vehicle, all steps that sound like they should already be covered by pre-trip inspections and then assessments at the destinations for these deliveries.

So why does every state use truck weigh stations?

• Taxes: Some states tax the cargo coming in on trucks, and the weigh-ins help them determine how much money to levy.
• Road & Infrastructure Safety: Different highways, roads, and bridges have varying weight capacities. When a truck exceeds that weight, it can cause that infrastructure to deteriorate, causing costly damage that also puts others at risk of damaging their vehicles and getting into accidents.
• Driver Safety: A truck that is loaded beyond the legal capacity is more difficult and dangerous for the driver to maneuver, which endangers the truck driver and anyone else on the road.

What Can Happen If a Truck Is Overloaded?

First, if a truck is improperly loaded or overloaded, this puts strain on the vehicle itself, wearing down the tires and other parts of the vehicle, leading to dangers such as tire blowouts and mechanical failure. An overly heavy truck is harder to steer and harder to brake, increasing the time it takes to come to a stop. Overall, the truck will be less stable and at a higher risk for cargo spills and rollover accidents. Any of these can be disastrous for the truck driver and any other motorists, as well as others in the vicinity of the road the truck is taking.

In situations that are already hazardous, such as inclement weather or dangerous roads, an overloaded, unstable, and straining truck is all the more likely to get into a serious accident.

Can Trucks Avoid These Weigh Stations?

One popular (and legal) way of avoiding these or at least streamlining the process is preselection, or pre-clearance. This is when a truck company files certain information with a preselection technology company and the Federal Motor Carrier Safety Administration (FMCSA). With this information on file, the trucker can drive over in-road weight sensors that get the vehicle’s overall weight, or gross weight. During this time their transponder, usually mounted by the windshield, will send the on-file information to the weigh station. The weigh station will then send a signal back to the transponder, either giving the literal green light that lets the driver skip the scales and inspection, or it flashes the red light that means the driver needs to stop on the scales and possibly wait for an officer to conduct an inspection. Sometimes, a truck driver will be selected at random to stop for inspection, just to make sure the preclearance process is honest and accurate.

The information that a transponder company and the FMCSA will have on file for pre-clearance includes:

• The truck company’s credentials
• Vehicle registration
• Insurance information
• The driver’s license
• The truck’s pre-load weight (also known as curb weight)
• Their Inspection Selection System (ISS) score

The ISS score can flag even preselected trucks for inspection. The higher the score, the higher the chance of being stopped. This score is determined by the truck company’s record of complying with Hours of Service (HOS), the driver’s physical fitness, any history of controlled substance usage, how well the truck is maintained, whether there is hazardous material on the truck, and so forth.

Another way that truck drivers may bypass weigh stations is by using an app that tells them where the weigh stations are so they can find alternate routes to bypass the stations. These apps can also let truck drivers know when weigh stations are open or not. If they’re closed, then the trucker can drive right past without issue.

Another instance where truckers can legally avoid weigh stations is when, because of traffic patterns, they aren't able to safely change lanes to access the station. In such cases, however, especially if it’s for congested traffic, the weigh station will probably be closed anyway.

What Happens If a Driver Misses a Weigh Station? Or Fails Inspection?

If a weigh station is open and a commercial truck illegally drives past, there are usually law enforcement vehicles nearby that will pull that driver over, give them a ticket, and force them to circle back to the weigh station.

Penalties for being overloaded or failing other aspects of an inspection depend on the nature and severity of any violations. They also depend on the state where the truck is inspected. Most commonly, trucks found weighing too much could be fined per pound of excess weight, leading to fines worth a few hundred dollars or more than $10,000. Repeat offenses will cost more. The driver could also get fired by their company, lose their commercial driver’s license (CDL), and in some cases even face jail time (certain inspections involve checking for drug and alcohol usage).

What Happens at a Truck Weigh Station?

The details can vary by state and whether the weigh station is a permanent one, or a temporary checkpoint with portable scales. Signs will always mark the spot, and there will also be indications of whether the station is open or closed, usually a sign with lights. As a truck driver rolls through, following the signs that indicate where to go, they will either stop on the scales to have the weight measured, or they will drive slowly over some weight-in-motion (WIM) scales. With WIM systems, drivers don’t have to come to a full stop, but instead can have their weight quickly assessed and sent to digital monitors both inside the station for on-site staff to look at and outside for the truck driver to see. If the truck is within the legal thresholds for gross weight (the truck and its fluids plus the weight of the driver, cargo, and any additional equipment), then the driver can carry on with their route, unless they’re also required to submit to further inspection.

Virtual weigh stations are growing more common in some states, however, which means that some weigh stations don’t have staff on site. Instead, much like with the WIM systems, the truck moves slowly across the scales, and these results and camera feeds are sent to another site. This allows for remote monitoring to ensure that trucks are compliant.

At stations with personnel on site, some trucks will be flagged either way to stop and wait for station officers to inspect their credentials and/or vehicles.

Weigh Station Truck Inspections

Whether these inspections are conducted by DOT officials or state highway patrol, there are several different types of inspections that a truck driver and commercial motor vehicle could have to undergo at a weigh station. Some inspections are more cursory than others, while some really eat up time.

The possible DOT or Department of Motor Vehicles (DMV) inspections one can go through include the:

1. North American Standard Inspection: The most time-intensive, thorough inspection, this requires certain documentation of the driver, from their CDL to a Medical Examiner’s Certificate (MEC) as well as a Skill Performance Evaluation (SPE) Certificate if needed. It also involves an alcohol and drugs inspection, a look at hours of service and the driver record, and the use of seat belts. There is also the 37-point inspection of the vehicle itself, from the headlamps and turn signals to the steering, brakes, cargo, exhaust systems, and so much more.
2. Walk-Around Inspection: While this may sound cursory, this inspection is almost as intensive as the level one inspection, the only difference being that the officer isn’t going to inspect under the truck when looking at its exterior systems. That means points like the vehicle’s suspension and frame aren’t inspected.
3. Driver/Credentials/Administration Inspection: For these, an officer needs to check the driver’s record; Hours of Service (HOS) logs; Record of Duty Status (RODS); carrier ID; and status. The officer will also check that the driver is using their seat belt and also check for alcohol and drug usage.
4. Special Inspection: This is a spot check for just one part of the vehicle. Each year, DOT selects which part of the vehicle needs to be inspected in this process.
5. Vehicle-Only Inspection: Here there is no driver assessment, just an inspection of the truck itself, as the name suggests. This type of inspection is most commonly done after an accident or arrest.
6. Radioactive Material inspection: This inspection is nearly as thorough as a level one inspection, but it has the specific purpose of looking out for signs of radioactivity in and around a commercial motor vehicle that has hazardous materials.

In more thorough inspections, officers will need to do more than measure a truck’s gross weight. They will also have to determine how much each axle weighs, and how much weight is being put on those axles. The less axles weigh, and the more space there is between axles, the more weight a truck can carry.

As lengthy as these processes can be, digital systems have made this process smoother. Back in the 1990s, an officer would have to weigh axle groups manually, writing down the weights by hand, and then checking a formula table to make sure that a truck of its size was compliant. They would also have to check through paper logs, which are much easier to fake than digital records.

Now with WIM systems and laser measurements, crucial data can be captured and displayed much more quickly. While officers still have to check a driver’s CDL, logbook, medical card, truck registration, fuel tax license, and so forth in person, many of these records are also digitized as well, streamlining the process.

Why Do We Have Truck Weigh Stations?

In many ways, the reason we need weigh stations is to make sure that trucking companies are caught when they set their drivers up for dangerous failures. Far too often, trucking companies are willing to push their drivers to violate hours of service, drive through dangerous fatigue, and drive with unsafe loads or poorly maintained vehicles. When these companies maximize cargo loads beyond what is safe, they are putting the risk of road damage and disastrous accidents onto their drivers, others on the road, pedestrians, and others in the communities through which these trucks drive.

While some states would have these stations anyway for taxes, or for when a more vulnerable stretch of road or a bridge ahead needs to screen vehicles, all these weigh stations also function to help keep trucking companies in check, ideally before their negligence leads to catastrophic accidents.