ICT Researchers Recommend Best Strategies for IDOT Effectiveness in Meeting Real-Time Information Dissemination Requirements

New federal requirements mandate that states establish a system for disseminating travel times, lane closures related to traffic incidents, lane- and road-closing construction, and road weather conditions to drivers in real time along interstates and key routes within a state. In addition, the information must be available 90% of the time and have an 85% rate of accuracy.

On behalf of the Illinois Department of Transportation (IDOT), Illinois Center for Transportation (ICT) researchers completed a two-phase study of Illinois’ current traveler information system and evaluated how best to meet these federal requirements. The study, Real-Time Information Dissemination Requirements for Illinois per New Federal Rule (R27-119), was led by Ryan Fries, associate professor of civil engineering at Southern Illinois University Edwardsville (SIUE).

“Because my area of expertise is intelligent transportation systems and because I was familiar with IDOT Bureau of Operations staff from the highway incident management research I did [in projects R27-064 and R27-118],” Fries explains, “I was very interested in conducting the real-time traffic and road conditions study.”

In the first phase of the study, Fries and his team developed tools and methods to measure compliance with the new federal rule. In the second phase, they led stakeholder meetings to guide identification of routes of significance in metropolitan areas.

Says Fries, “In the near future, IDOT will be required to provide real-time traveler information along these routes of significance, in addition to their interstates,” so it was important to ensure that the state not only identified those routes using a thoughtful approach, but also that everyone was on the same page as to how to bring those routes up to compliance.

When asked what challenges Fries and his team faced in completing this project, he had this to say: “Data availability was a challenge during the second phase. The data we needed was not always available for some of our evaluations. We were challenged to find new and different sources to provide meaningful guidance on those types of traveler information.”

Despite those challenges, they were able to bring the second phase to successful completion and provide IDOT with the knowledge and data it needs to move toward compliance with the federal rule.

As a result of this project, IDOT and other key stakeholders throughout Illinois can help ensure compliance with this new federal rule. More importantly, drivers have assurance that they are getting timely and accurate travel information, which could help alleviate traffic congestion throughout the state and especially in major metropolitan areas.

Bruce Carmitchel, IDOT Bureau Chief of Planning, says, “The SIUE research provides IDOT with a strategy and road map to meet the requirements contained in both phases of the USDOT Real-Time System Management Information Program Final Rule. The SIUE research has also supplied IDOT with the necessary sampling techniques for us to periodically measure the accuracy of the traveler information that is being made available for dissemination so that IDOT remains in compliance with the federal rule.”

Carmitchel adds that he was impressed with how well the SIUE researchers worked with IDOT stakeholders and members of the Technical Review Panel in conducting this research.


Accidents can cause road closures lasting hours. Alerting motorists to potential delays allows them to plan alternate routes or to know to expect congestion.

Accidents can cause road closures lasting hours. Alerting motorists to potential delays allows them to plan alternate routes or to know to expect congestion.