10/26/2026 McCall Macomber
Written by McCall Macomber
An Illinois Center for Transportation team, led by director Imad Al-Qadi, has developed a roller-mounted ground-penetrating radar system that can measure real-time density of flexible pavement, a key indicator of long-term pavement performance.
Ground-penetrating radar is a nondestructive test that sends electromagnetic waves into pavements. The reflected waves can be used to calculate dielectric properties related to material composition.
Al-Qadi and colleagues have pioneered the development and use of GPR tools for pavement applications over the past four decades. Other areas in which they’ve developed GPR tools for pavements include their groundbreaking work on detecting moisture content and defects as well as predicting layer thicknesses and density.
Their patent-pending system will allow contractors to see real-time pavement density and continuously measure the progression of pavement compaction during construction, allowing them to more accurately achieve a target density.
“Density is used for quality control and quality assurance in all U.S. states and all over the world. This system will provide an opportunity for contractors to ensure they receive incentives for their work and avoid any penalties while on a project. Deploying this system will ensure users achieve the expected road quality, making pavements safer, smoother and more resilient,” Al-Qadi said.
Current quality control and quality assurance methods are time-consuming, only cover very small parts and allow for limited adjustments if needed. The roller-mounted GPR system will allow users to measure an entire pavement span and correct density during construction.
Other expected benefits include reduced costs and environmental impacts by optimizing the number of roller passes needed to compact pavement and decreasing fuel usage.
Operators were top of mind when Al-Qadi and colleagues were developing and validating the system. The ICT team worked directly with roller operators to optimize the mount and to reduce the calibration needed to operate it.
“Many people have worked over the years to contribute to the successful development of this system,” Al-Qadi said. “This accomplishment could not have happened without the contribution of our brilliant students and the support we received from ICT engineers and staff as well as from transportation agencies and industry members.”
The ICT team will hold a free online workshop on Thursday, November 12 to discuss the system. Learn more and register here.
Al-Qadi and colleagues acknowledge the support of those who helped contribute to the success of the roller-mounted ground-penetrating radar system. The Federal Highway Administration’s Accelerating Market Readiness program sponsored the validation of the system, while its STIC Incentive program allowed researchers to work with the Illinois Department of Transportation to further validate and refine it. The University of Illinois Urbana-Champaign’s Office of Technology Management also awarded funding to validate the concept through the Illinois Proof-of-Concept Program.
They recognize the support and professionalism of the following individuals: Jeffrey Zaharewicz and Ryan Buck (FHWA); John Senger, Chad Nelson, Brian Hill, and the quality assurance team (IDOT); Brian Gallagher, Gage Crawford, and Susana Gonzalez (Gallagher Asphalt); Steve Rubio, Hakeem Gill, Jacob Truax, and Sal Castelan (Gallagher Asphalt roller operators); Jeff Kern (Open Roads); John Miller (Open Roads roller operator); John Lynch and Jason McKee (Iroquois Paving); Nikki Kenney (Iroquois Paving roller operator); Pablo Sanchez (Chicago Testing Laboratory); Neal Proctor and the quality control team (United Contractors Midwest); and Shylar Boze (UCM roller operator). They also acknowledge the work and contributions of ICT research engineers Greg Renshaw, Mohsen Motlagh and Uthman Mohamad Ali as well as the numerous graduate research assistants who worked on and assisted with the development of the system over the years. Special thanks to the current GPR team led by research scientist Lama Abufares and supported by graduate students Yihan Chen, Gaurav Bhusal, and Kazi Khohinoor Akter Kripa.