Researchers at the Texas A&M Transportation Institute (TTI) are advancing how Texas designs and maintains its highways through an innovative portable weigh-in-motion (pWIM) system.

Led by TTI Pavement Analytics Program Manager and Research Scientist Lubinda Walubita, the research addresses a key challenge: the need for accurate, site-specific, project-level truck weight data to support optimal pavement designs. Without accurate data, agencies risk overdesigning roads — increasing construction costs — or underdesigning them, which can lead to premature failures and higher maintenance costs.

The need for improved truck-load measurements became especially clear during the energy boom that began around 2012, when large areas of South and West Texas experienced significant increases in truck traffic and axle loads. As a result, many miles of thin pavement were severely damaged. The Texas Department of Transportation (TxDOT) initiated research with TTI to develop site-specific truck-load measurement systems for pavement design engineers.

Responding to that need, Walubita developed a system based on piezoelectric sensors. Once the basic system was demonstrated, researchers addressed another challenge: developing a mounting system that could be deployed effectively across the different pavement surfaces found throughout Texas, including asphalt, concrete and seal-coated roadways.

Prior to installation, the sensors are calibrated at the Texas A&M-RELLIS campus as well as at the highway site. Installation takes approximately one hour, and the system typically collects data for a minimum of one week. Truck type, axle weights, gross vehicle weights and speeds can also be monitored in real time through linked computers. The collected data is then processed to provide TxDOT designers with an estimate of total truck loads over the pavement’s design life, which is typically 20 years.

To support statewide use, researchers developed standardized procedures for system deployment, field sensor calibration, data analysis and quality control, along with hands-on training through a demonstration station at the RELLIS campus. pWIM systems have now been installed in every TxDOT district. Collected data is also incorporated into a Google Earth-based display system, where district designers can access site-specific information or districtwide averages.

A recent demonstration for the Texas Transportation Commission highlighted the system’s real-time capabilities and represented an important milestone for the project. TTI researchers installed a pWIM system on State Highway 6 just north of Old San Antonio Road and transmitted live roadway video and truck-weight data from the site to the commission meeting in Austin. For the first time, commissioners were able to watch trucks traveling on the highway while simultaneously seeing their measured weights in real time.

Researchers also installed a pWIM system outside TxDOT’s Greer Building in Austin to provide an additional hands-on demonstration of the technology. Together, the demonstrations showed how the portable system can quickly capture field conditions and provide transportation decision-makers with immediate, location-specific truck-load information.

The system is currently being implemented through interagency agreements with TxDOT’s Maintenance Division. By providing districts with more accurate information for pavement design, pWIM supports more data-driven and cost-effective infrastructure decisions. Improving how truck-traffic loads are measured and understood can help extend pavement life, reduce costs and strengthen the long-term performance of Texas highways.