US DOT research strengthens sustainability and innovation in transportation

Three Illinois Center for Transportation faculty leads are working on new federally funded projects that advance sustainable pavement design, resilient materials and smarter construction technologies.

Designing Low-Carbon Asphalt Mixtures and Monitoring Their Field Performance

A study led by ICT asphalt materials lead and University of Illinois Urbana-Champaign assistant professor Ramez Hajj explores ways to design and evaluate low-carbon asphalt mixtures by incorporating reclaimed asphalt pavement and other sustainable materials.

Sponsored by the Maryland Department of Transportation, Hajj and researchers at Morgan State University will examine how higher RAP contents affect the mechanical performance and durability of asphalt pavements while identifying mix designs including rejuvenators that maintain high performance. The team will also assess the economic and environmental impact of using these materials. They will develop a strategic framework to guide the Maryland State Highway Administration on how to classify low-carbon asphalt materials.

The project is expected to end November 2026.

Evaluating the Effectiveness of Geosynthetics in Controlling the Detrimental Effects of Slow-Moving and Turning Traffic

Erol Tutumluer, ICT transportation geotechnics lead and Illinois Abel Bliss Professor in Engineering, is evaluating how geosynthetics, particularly geogrids, can improve pavement performance in areas exposed to slow-moving or slow-turning traffic, conditions that often lead to early surface distress.

Through laboratory testing and full-scale field evaluations, the DOT-sponsored project will assess how geosynthetics improve lateral restraint, stiffness and load distribution. The findings will support new design guidelines and construction strategies for Indiana DOT that help extend pavement life and reduce maintenance needs for high-stress pavement locations such as roundabouts and intersections.

The project is expected to conclude June 2027.

Roller-Mounted GPR for Asphalt Pavement Quality Control and Assurance

Imad Al-Qadi, Illinois Grainger Distinguished Chair in Engineering and ICT director, is leading a study sponsored by Illinois Department of Transportation and the DOT that develops a roller-mounted system for ground-penetrating radar that predicts asphalt pavement layer thickness density.

Unlike traditional quality control and assurance methods that rely on time-consuming spot measurements or taking samples after construction, the ICT-developed system is designed to monitor real-time asphalt pavement density during construction. Al-Qadi’s team will validate the system through statewide projects as well as prepare training materials for users of the system.

Successful adoption of the technology will help achieve target density for asphalt without under- and over-compacting it — saving time, costs and energy — helping to reduce quality control and assurance disputes between contractors and agencies.

The project is planned to end September 2026.