The Grainger College of Engineering
Illinois Center for Transportation

New ICT-IDOT reports

6/13/2024 McCall Macomber

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-SP65: Review of Low-Clearance Early Warning Device Options for Illinois
Yanfeng Ouyang, University of Illinois Urbana-Champaign
Kyle Armstrong, Illinois Department of Transportation

Early warning devices on or in advance of bridges alert drivers of low clearances and aim to reduce bridge strikes. Early warning devices may include lidar, radar or visual signals.
Early warning devices on or in advance of bridges alert drivers of low clearances and aim to reduce bridge strikes. Early warning devices may include lidar, radar and/or visual signals.

The state of Illinois recently passed legislation requiring IDOT to establish a pilot program to install devices on or near bridges over roadways that warn drivers of low clearances.

The aim of this project was to help identify potentially effective devices and technologies that can be installed to help reduce bridge strikes in Illinois. Researchers examined various technologies and devices used to provide early warning of low-clearance structures as well as their effectiveness.

Decreasing the number of bridge strikes reduces costly damage to state property and reduces road and lane closures caused by damaged structures that cannot be immediately repaired.

R27-SP57: Electrification of Illinois Transit: Bridging the Gap with Heavy-Duty Technician Training Initiatives
Reggie Greenwood, Governors State University
Charles Abraham and Zoe Keller, Illinois Department of Transportation

IDOT supports transit agencies in 101 of 102 counties across Illinois through operational, capital and planning funding.
IDOT supports transit agencies in 101 of 102 counties across Illinois through operational, capital and planning funding.

A statewide lack of maintenance technicians has hindered efforts to maintain transit vehicles at the highest quality, leading to occasional outsourcing for vehicle maintenance.

The aim of this project was to work with transit agencies and other stakeholders to support maintenance technicians in Illinois. Researchers worked with educational institutions and workforce development organizations to determine how IDOT can support a system that recruits, trains, employs and retains maintenance technicians on a larger scale, especially for alternative fuel transit vehicles.

Better supporting maintenance technicians will reduce premature vehicle failures as well as save on short- and long-term maintenance and capital costs.

R27-235: Thickness Design for Cement-Treated Base Pavements
Marshall Thompson, University of Illinois Urbana-Champaign
James Krstulovich and Tim Peters, Illinois Department of Transportation

Cement-treated base pavements are typically constructed using full-depth reclamation — a cost-effective, environmentally sustainable process in which existing pavement layers (asphalt, chip seals, aggregate, soil) are recycled in place.
Cement-treated base pavements are typically constructed using full-depth reclamation — a cost-effective, environmentally sustainable process in which existing pavement layers (asphalt, chip seals, aggregate, soil) are recycled in place.

This project’s goal was to develop a thickness design procedure and supporting policies for cement-treated base pavements for use by local roads agencies. The developed design procedure will result in more consistent and better performing CTB pavements, as there are currently large variations in the thicknesses and pavement sections constructed with this technique.

Effective procedures will provide better guidance for the design and construction of CTB pavements, potentially resulting in cost savings and improved performance. Local roads agencies will benefit significantly from improved guidance concerning the most effective utilization of full-depth reclamation with cement.

R27-SP55: Development of Guidelines for Messages in Dynamic Message Signs to Improve Safety, Compliance, and Avoid Distraction
Yanfeng Ouyang, University of Illinois Urbana-Champaign
Sean Martschinke, Illinois Department of Transportation

In 2021, there were 1,341 fatal injuries on Illinois roads, a 12.2% increase from 2020, according to the Illinois Department of Transportation.
In 2021, there were 1,341 fatal injuries on Illinois roads, a 12.2% increase from 2020, according to the Illinois Department of Transportation.

Dynamic message signs are primarily used to inform drivers of traffic impacts, road work, amber alerts and weather conditions. These signs are also used to promote safe driving habits and to help reduce fatal crashes on Illinois roads.

The aim of this project was to see if creative messaging that promotes save driving habits, such as pop culture references, can change a driver’s behavior and reduce crash frequency. Researchers reviewed the messaging practices of other transit agencies as well as surveyed drivers through a questionnaire and driving simulator.

Evaluating the effectiveness of creative messaging on dynamic message signs will allow IDOT to create messaging that has a positive and lasting impact on driver behavior.

R27-210: Cone Penetration Testing for Illinois Subsurface Characterization and Geotechnical Design
Jorge Macedo, Sheng Dai and Paul Mayne, Georgia Institute of Technology
Brian Laningham and Brad Hessing, Illinois Department of Transportation

Engineers use the cone penetration test to determine detailed information about the properties and strength parameters of soil.
Engineers use the cone penetration test to determine detailed information about the properties and strength parameters of soil.

The cone penetration test, which collects data continuously, is faster and provides more consistent data than the currently used standard penetration test, in which a hollow stem auger is positioned into the ground at 2.5- to 5-foot intervals to retrieve soil samples.

The goal of this project was to develop guidelines and a manual for the cone penetration test.

These resources will help IDOT obtain more reliable data and lower the risk in roadway and geotechnical designs, thereby reducing project expenses.

R27-SP59: Field Performance of Unacceptable Hot-Mix Asphalt Test Parameters
Ramez Hajj, University of Illinois Urbana-Champaign
Douglas Dirks, Illinois Department of Transportation

A contractor drills into an asphalt sample to measure its density. IDOT uses three tests to measure the acceptability of hot-mix asphalt: pay for performance, quality control for performance, and quality control and quality assurance.
A contractor drills into an asphalt sample to measure its density. IDOT uses three tests to measure the acceptability of hot-mix asphalt: pay for performance, quality control for performance, and quality control and quality assurance.

IDOT uses mixture volumetric and in-place density test parameters in the hot-mix asphalt quality management programs for acceptance. In the acceptance process, IDOT has acceptable limits associated with four test parameters: air voids, field voids in the mineral aggregate, in-place density and dust to asphalt binder ratio.

The goal of this project was to evaluate the relationship between field performance and mixture volumetric and in-place density test parameters (including the acceptable limits parameters) used in the IDOT acceptance process. Additionally, researchers recommended that IDOT monitor hot-mix asphalt field performance in the future.

R27-230: Performance and Design of Continuously Reinforced Concrete Pavements
Jeffery Roesler, University of Illinois Urbana-Champaign
Charles Wienrank, Illinois Department of Transportation

Photo courtesy of the Concrete Reinforcing Steel Institute. Paving continuously reinforced concrete pavement — a predominant pavement type on interstates in Illinois — around reinforcing steel using a slipform paver.
Photo courtesy of the Concrete Reinforcing Steel Institute. Paving continuously reinforced concrete pavement — a predominant pavement type on interstates in Illinois — around reinforcing steel using a slipform paver.

Instead of using joints sawed at regular intervals to control cracking, continuously reinforced concrete pavement uses longitudinal steel reinforcing bars within the concrete to tightly hold the transverse cracks that develop in the slab, resulting in a smoother, more durable roadway that requires less maintenance.

The aim of this project was to use the latest mechanistic-empirical techniques to develop updated procedures for IDOT for the design of new CRCP and unbonded CRCP overlays. The updated design procedures will further improve pavement performance and reduce costs to build and maintain roadways.

R27-233: Mechanistic-Empirical Design Procedures for Flexible Pavements
Ramez Hajj and Marshall Thompson, University of Illinois Urbana-Champaign
Charles Wienrank and Brian Hill, Illinois Department of Transportation

Flexible, or asphalt, pavements provide smooth, quiet and skid-resistant roads for the traveling public.
Flexible, or asphalt, pavements provide smooth, quiet and skid-resistant roads for the traveling public.

Design procedures and policies for flexible (asphalt) pavements are continually evolving.

This project reviewed IDOT’s current design method and policy documents. Researchers discovered via lab testing of contemporary hot-mix asphalt mixtures that changes to design inputs may be needed to ensure that the design processes reflect the latest technology. They recommended further research to characterize IDOT mixtures and provide guidance on policy updates.

Improved pavement designs are expected to result in cost savings and improved long-term pavement performance.