One of the most difficult jobs for a trucker is keeping the tractor-trailer within the legal weight requirements. There is a standard maximum weight for commercial vehicles on the Interstate Highway System, and it is as follows:

Single Axle: 20,000 pounds

Tandem Axle: 34,000 pounds

Gross Vehicle Weight: 80,000 pounds

This simple standard weight law works well when shippers have a scale, or there is a scale nearby. However, when the shipper doesn’t have a scale and loads the trailer overweight, it is the trucker who gets fined. That’s just the way it is… at least for now. So, what can truckers do to ensure they are always within the weight requirements? Experienced drivers have a few tricks up their sleeve that allow them to “eyeball” a shipment and know the approximate weight, however beginners would do well to learn a few rules of thumb before hitting the road:

#1 Never Take Chances

While safety should always be your first priority, you also don’t want to leave your driving record up to chance, or your wallet, for that matter. For instance, a cop may pull you over on the way to a scale, or it may not be possible to find a scale before crossing an official weigh station. If this happens and you’re overweight, you can bet you will be the one receiving a ticket. Currently, overweight fines are about $500. So, do your homework and know how much your truck weighs (both fueled up and empty), what it looks like with the correct weight, and what it looks like when it’s close to overweight. This article at Life As A Trucker.com has some great advice for new drivers learning how to estimate their weight. You can also take this simple advice from an experienced trucker at www.truckingtruth.com:

“Some loads don’t require weighing if its under 40000 and you know how to read your air suspension gauge. Rule of thumb: under 20000 8th hole, 20000 to 30000 7th hole 30000 to 40000 6th hole and 40000 5th hole; works every time. Except when they screw the loading. That’s why its important to know how they load your trailer and where its loaded too. Being with a company awhile you will learn your freight, shippers and how its loaded.”

#2 Know your shipper

If it’s a new shipper, be sure to look at what they are loading, how much they are loading, and how they are loading it. If they ask how much weight you can haul, give yourself some wiggle room. For instance, if you weigh 32,000 pounds empty, then don’t tell them 48,000 pounds. That gives you absolutely no wiggle room, and it’s very unlikely that the shipper will know exactly how to position its products to ensure the weight on your axles is correct. Once you get to know your shippers better, you will remember who has scales, who doesn’t, who loads correctly and who to keep an eye on.

#3 Communicate with your dispatcher

Let the dispatcher know if the shipper has no scale. They may need to be informed of route changes, and they also might be able to locate a nearby scale for you.

#4 Know how to find nearby scales

There are quite a few strategies for finding nearby scales, but first you need to know about the two main types of scales: CAT scales and independent scales. CAT scales are always accurate and can give you a legal guarantee that your shipment is under the correct weight. Independent scales do not come with a guarantee, but they can give you documentation that you did indeed weigh the truck. Independent scales can be found at places such as gravel plants, landfills, recycling centers, feed mills, and household movers. To find a nearby scale, you can ask the shipper, your dispatcher, or use the following tools:

Google Maps

DAT Trucker Services

Truckstop Guide

Rand McNally GPS

Or, if you have a smartphone, then browse the truck driving apps for the best scale finder for your phone. Like all things, there’s an app for that.