FEATURE: Protecting roads from heavy vehicles with weighing technology

Texan roads are under pressure. Tom Stone looks at how new research analyzes border controls for heavy vehicles, calculates permit revenues vs road repair costs and recommends ways to protect the state’s highways for the future

Politics aside, the 1,254-mile Texas-Mexico border has long required an array of safety and security measures that must operate 24/7 to manage the flow of over 14,000 commercial vehicles that cross northbound daily. Even if this tide reduces in the face of tariffs from the Trump administration, it will still be critical to maintain security systems at the border, where ITS serves as the first line of defense in ensuring compliance and security.

A vast array of technology helps the border force, who must keep a watch out for everything from illegal immigrants to contraband, every minute of every day. When it comes to vehicle compliance, spotting smuggling and protecting roads from overloaded vehicles, some the technologies at the heart of this system are weigh-in-motion (WIM) devices, augmented by static scales.

A growing awareness of the critical nature of the border crossing, which added $67.3 billion to Texas Gross Domestic Product (GDP) in 2019 and is projected to more than quadruple to almost $300 billion in GDP by 2050, prompted the Texas legislature to enact Texas House Bill 4422 (HB 4422), which directed the Texas Department of Transportation (TxDOT) to conduct a study on public safety, border security, and transportation infrastructure from Texas-Mexico border crossings.

The study was carried out with the assistance of the Texas A&M Transportation Institute (TTI) and included input from the Texas Department of Public Safety (TxDPS), Texas Military Department and local law enforcement agencies. The HB 4422 Study reported its findings in November 2024, and found critical gaps in enforcement technology

Of the eight CMV border crossings where TxDPS has a presence, all were found in the report to “have missing or non-operational technology” that should be there to “enhance inspection capabilities.” This includes crucial WIM systems, which allow authorities to measure vehicle weights without requiring them to stop – a significant efficiency advantage in high-volume settings.

These weighing systems serve as part of an integrated security approach that helps identify potential smuggling activity. The report notes that “human smuggling and controlled substance smuggling were the two most common crimes reported by TxDPS” among the 322 individuals arrested for CMV-related crimes between 2018-2023.

Weighing technologies work alongside other screening tools like license plate readers, thermal cameras, and hazmat placard readers to create a multi-layered security approach.

The cost of weight

Even in if a truck driver is not complicit in a crime as egregious as smuggling, simply driving a vehicle that is over its permitted weight can have a significant economic impact, particularly when it comes to later road maintenance to repair damage it may cause.

Quantifying this damage was the subject of another study mandated by the Texas legislature – The HB 2223 Study on motor vehicle impacts on the roads and bridges of Texas. One of the key contributors to this work was Brianne Glover, a division head and senior research scientist at the Texas A&M Transportation Institute (TTI).

“You see trucks out there every day – when you’re on your way to work, when you’re running errands – and you don’t really think about them, but they are moving constantly,” says Glover. “They’re bringing goods to stores, they’re bringing goods to your home. They’re bringing goods to other manufacturers that may use a part to produce some other good. And so trucks support many major industries, especially here in Texas.”

“Commercial trucks and oversized trucks have more road damage cost associated with them than revenues. So, there is a loss there. There is a deficit”

The HB 2223 Study examined in the financial relationship between vehicles and road infrastructure. It separated vehicles into three categories: passenger vehicles, commercial motor vehicles (typically 18-wheelers), and oversize/ overweight vehicles. This last category did not include trucks that were illegally overweight, which would have been harder to study, but instead looked at those that had obtained a special permit to operate over 80,000lb.

“The legislature wanted to know how much damage trucks did and what the cost of that damage was,” says Glover. “And so that was something we called a ‘consumption cost’. We then compared that to the actual revenues that those vehicles brought in to the State of Texas to see if they were covering the damage they do to roads, basically, if they were paying too much, or too little.”

Currently CMVs (commercial motor vehicles) must pay for road use in Texas based on fixed fees, such as vehicle registration fees, which go up the larger the truck is. Large trucks will also pay more fuel tax simply because they burn more fuel.

Every oversized truck trip also requires a permit. Companies that frequently move heavy loads can buy quarterly or annual permits instead of single-trip ones.

Glover’s research revealed a significant financial imbalance in this trucking payment system. “Commercial trucks and oversized trucks have more road damage cost associated with them than revenues. So, there is a loss there. There is a deficit,” Glover explains.

According to the research, commercial trucks cause about $2.2 billion in overall consumption costs (damage to roads and bridges) annually, but only bring in a little over $2 billion in revenue. “So we are short by about $130 million when you compare the two,” says Glover.

For overweight vehicles, “their consumption cost is a little less than $300 million annually,” she notes, with a similar gap of “about $168 million” between their costs and the revenue they generate.

Frontline technology

With the cost of overweight trucks to the state shown in the HB 2223 Study, recommendations of the HB 4422 Study to invest in weighing technology at the border come into sharper focus

The HB 4422 Study recommends to: “Deploy virtual weigh-in-motion (VWIM) throughout border region and construct pull-over areas for CMV inspectors to perform roadside inspections” with a funding need of $5.4 million. Virtual WIM refers to any WIM system with camera enforcement backup.

The HB422 Study also calls for greater investment in static scale sites, which it estimates to require around $4.5 million investment. It recommends setting up “static sites for mobile patrols along CMV routes to enhance the efficiency and effectiveness of commercial vehicle inspections.”

Closing the gap

A key part of Glover’s research involved developing potential solutions to address the funding gap. Her team identified several options for policymakers to consider, including adjusting permit fees for oversized/overweight vehicles, either with a blanket increase or by raising annual fees more than single-trip fees, or increasing vehicle registration fees based on weight.

Implementing a vehicle-miles traveled (VMT) fee, where vehicles pay per mile driven was also considered. “You can vary fees for different categories, so a truck would pay a higher price per mile than a passenger vehicle,” says Glover.

A VMT scheme could be augmented further with the addition of actual weight into the equation creating a weight-distance tax. While the legal mechanisms for this do not yet exist in Texas, Glover points out that “there are four states that currently have those: Kentucky, New York, New Mexico, and Oregon.” While such systems currently rely on registering the overall capacity of a vehicle and the manual reporting of VMT, in the future dynamic weighing with WIM coupled with satellite positioning could create a completely automatic system.

The political balancing act

The challenge for Texas authorities is maintaining rigorous security, while facilitating the swift movement of legitimate commerce. As the HB 4422 Study of border crossings states, “If implemented, the recommendations from this study will result in more efficient, safe, and secure border trade.”

Similarly, Glover’s research highlights the need to balance infrastructure funding with economic realities. “Trucks support major industries in Texas to the tune of nearly half a trillion dollars in economic output.,” she says.

This economic contribution creates a challenging political situation, where the profits of the motor carriers and the benefits to the economy and consumers must be balanced against the cost to the DOT in maintaining roads, raising questions of whether public money should subsidize private profit if this can be justified by overall public good.

“It very much is [a political hot potato],” Glover acknowledges. “That was part of the original study, too. We did look at the economic impacts, because if you were to raise the fee, does it just get passed on to the public or to the consumer purchasing those goods? The trucking industry is huge here in the state of Texas, we’re very large. And so that’s the main way we move goods. And a lot of goods that come from Mexico and go on to the rest of the US.”

The conversation continues, and while firm action on the matter is yet to materialize in Texas, the issue continues to be a live one. “Our legislature is in session right now, which only happens for a few months every other year,” says Glover. “And I know there have been a few bills to do with different oversize trucks and what would it take to increase the weight limit. And so, I know it’s a constant topic for discussion.”

As both reports make clear, for the thousands of commercial vehicles that cross Texas highways daily and TxDOT itself vehicle weight it a critical factor that can determine costs, profits and ultimately the deterioration rate of roads. “We all know they have their normal life cycle costs,” says Glover, “but if we can keep from speeding that up, that’s always a plus.”

This article first appeared in the May 2025 issue of TTi