New ICT-IDOT reports
7/20/2025
Illinois Center for Transportation is pleased to announce the publication of reports from the following Illinois Department of Transportation-sponsored projects, in order of publication.
R27-SP69: IDOT Environmental Impacts Needs Assessment
David Zaya, Eric Janssen, Paul Marcum, Wendy Schelsky, Elliott Smith and Jack Zinnen, University of Illinois Urbana-Champaign
Jake Vancil, Illinois Department of Transportation
Illinois roadside right-of-way provides important habitats that support biodiversity, including flora and fauna native to the state. Some of these species are considered threatened or endangered and legally protected.
The goal of this project was to develop management strategies to protect these species and enhance resource-rich sites, known as special management areas, within and along IDOT right-of-way.
Researchers developed a reporting strategy of management activities conducted within IDOT right-of-way, developed prioritization of SMAs for management and standardized conservation measures to help IDOT address regulatory compliance, used spatial analysis to identify these SMAs, and explored partnership opportunities on how to further manage these areas.
R27-234: Effectiveness of Geosynthetics in Soil/Aggregate Stabilization—Evaluation Using Bender Element Sensor Technology
Erol Tutumluer, University of Illinois Urbana-Champaign
Heather Shoup and Andrew Stolba, Illinois Department of Transportation
This project evaluated the strength gained between a layer of geosynthetic material and the soil or aggregate used to construct subgrades and subbases of roadway pavements.
Researchers used bender-element sensor technology, which sends a shear wave through a prepared test specimen and measures the speed of the shear wave, to evaluate pavement’s stiffness and strength. They developed draft test procedures, a break-even cost tool and design guidelines that can be applied to designing and constructing subgrades and subbases for pavements.
Optimizing geosynthetic layers may allow engineers to construct thinner aggregate layers while maintaining pavement performance, reducing the cost to construct pavements as well as potentially improving the quality and reliability of pavements.
R27-SP70: Understanding Wildlife-Vehicle Collisions in Illinois
Kirk Stodola, Melony Barrett and Peg Gronemeyer, University of Illinois Urbana-Champaign
Bradley Daugherty, Illinois Department of Transportation
Wildlife-vehicle collisions are a common and costly occurrence on U.S. roadways, the most significant of which occur with deer.
This research aimed to better understand wildlife-vehicle collisions in Illinois and to identify mitigation strategies. Researchers reviewed data on wildlife-vehicle collisions in Illinois, identified areas where those collisions are most common as well as influencing factors, and identified mitigation strategies to reduce collisions.
Reducing wildlife-vehicle collisions is expected to decrease injuries and fatal injuries from those collisions as well as reduce the amount spent on damages.
R27-259: State Department of Transportation Support for Operationalizing Transit Signal Priority
Kouros Mohammadian, University of Illinois Chicago
Mohammad Miralinaghi, Illinois Institute of Technology
Alireza Talebpour, University of Illinois Urbana-Champaign
Charles Abraham, Illinois Department of Transportation
Taqhi Mohammed, Pace Suburban Bus
Transit signal priority shortens or lengthens timed signal phases on traffic lights to give priority to transit vehicles with onboard transponders. This priority helps buses adhere to their operating schedules and reduces travel times for riders. Coordinated use of transit signal priority within northeastern Illinois can lead to new express bus services in congested urban and suburban corridors.
The researchers explored potential obstacles and solutions for improving transit signal priority implementation in Illinois. They surveyed other state agencies’ transit signal priority practices and developed best practices aimed to increase collaboration among implementing agencies of transit signal priority in northeastern Illinois, including IDOT.
R27-255: Illinois Department of Transportation’s Seeding Standards and Best Management Practices
Jeffrey Matthews and Rabin Bhattarai, University of Illinois Urbana-Champaign
Scott Hall, Illinois Department of Transportation
IDOT maintains nearly 16,000 miles of roadway and adjacent right-of-way, a significant amount of which is vegetated. Much of this vegetation is non-native turfgrass, which is planted to stabilize soils and to increase safety for vehicles that leave the roadway.
This project determined the long-term outcomes of vegetation in IDOT’s right-of-way. Researchers combined a survey of previous right-of-way plantings in Illinois with field trials of planting mixtures to determine cost-effective seeding mixtures and planting recommendations for revegetation of the right-of-way in various environmental settings.
Providing this knowledge will help guide new recommendations to enhance seeding success and minimize the spread of invasive plants in right-of-way areas.
R27-252: Impact of Commercial Electric Vehicles on Flexible Pavement Performance
Angeli Jayme and Imad Al-Qadi, University of Illinois Urbana-Champaign
Jamie Hernandez-Urrea, Marquette University
John Senger, Illinois Department of Transportation
This project aimed to better understand how electric commercial vehicles like semitrucks will affect asphalt pavements. Electric semitrucks will carry additional weight from large battery packs and will have increased capacity for torque and potentially different weight distributions.
Researchers examined the weight distributions and torque capabilities of these new vehicles and conducted large-scale testing and computer modeling to determine the effects on the pavement.
The outcomes will help IDOT become ready for the electrification of the commercial fleet, helping save time and money once electric commercial vehicles are in operation.
R27-226: Residual Capacity of Precast Prestressed Concrete Deck Beams with Transverse Cracks
Bassem Andrawes, University of Illinois Urbana-Champaign
Robert Perkins, Illinois Department of Transportation
Precast, prestressed concrete deck beams can develop transverse cracks when overstressed, indicating a loss of prestress.
The project’s goal was to develop guidelines to determine PPC deck beams’ remaining capacity if they are overstressed and transverse cracks are present.
The research will allow IDOT load-rating engineers to accurately load rate PPC deck beams with transverse cracks, which will assist with making decisions about whether the bridge should be open to traffic and/or if an allowable weight limit restriction is required.
R27-SP67: Avoiding and Minimizing Impacts to Aquatic Resources through Construction Design Standards
Dusty Swedberg and Wendy Schelsky, University of Illinois Urbana-Champaign
Vincent Hamer, Illinois Department of Transportation
Federal and state policies require construction projects to minimize, avoid or mitigate effects to threatened and endangered species.
This project identified designs and standards for bridge construction that will avoid or minimize impact to aquatic species. Researchers identified crossing designs that support aquatic life and allow passage while achieving the desired structural integrity.
Acceptable designs would increase permit turnaround time, provide safe crossings for the traveling public and ensure aquatic resources are allowed to move and flourish.