4/1/2026 McCall Macomber
Written by McCall Macomber
The state of Illinois enacted legislation in 2022 that established a task force to investigate compliance with the Move Over Law, also known as Scott’s Law.
One of the task force’s recommendations is to deploy digital alert systems that notify vehicles of the real-time presence of roadside hazards, such as stopped emergency or roadway maintenance vehicles, through navigation apps or in-vehicle notifications.
An Illinois Center for Transportation and Illinois Department of Transportation project aimed to measure the effectiveness of digital alert systems with law compliance. Juan Pava, IDOT’s Safety Programs Unit Chief, and Alireza Talebpour, University of Illinois Urbana-Champaign associate professor, led the effort.
“The task force was very excited about the possibility of implementing some of these technologies in Illinois,” Pava said. “At the same time, we had doubts about the impact of these alerts.”
“IDOT stepped in, and through ICT, we established this project in which the objective was to be able to get a quantified benefit on if these technologies helped how drivers approach a vehicle on the side of the road with and without digital alert warnings,” he added.
Talebpour’s team collected real-world data on Illinois freeways under multiple scenarios involving emergency vehicles and digital alert systems. Using aerial videography from a helicopter, they recorded responses from thousands of vehicles as they approached and passed planned stationary vehicles on freeway shoulders.
They monitored two sections on Interstates 80 and 55 in 2024 and 2025, respectively, with and without a stationary vehicle present on the shoulder. When a vehicle was present, the researchers tested drivers’ responses when using only emergency lights, both emergency lights and digital alerts, and no alerts or lights.
The I-55 testing took place over three days, with each day focusing on different variables: a police vehicle, an IDOT maintenance vehicle, and a police vehicle near on-ramp and off-ramp locations.
Talebpour’s team used computer vision — a field of artificial intelligence in which computers are trained to understand and interpret data from images or videos — to generate data from the footage on drivers’ speed and lane adjustments.
The technique measured how many vehicles passed through each test scenario as well as when and how many drivers took a certain action.
Use of emergency lights and digital alert systems consistently resulted in vehicles changing lanes and slowing down earlier and more smoothly.
“Now we know that there is a quantifiable safety benefit to investing in these types of technologies, this project will allow IDOT to make informed decisions into what works, what doesn’t and further justify some of the investment in improved technologies,” Pava said.
“This research helps ensure that we’re (IDOT) being good stewards of funding, and then we continue to ensure that if we are making investments in technology, that they are also supported by data,” he added.
Read the report for the IDOT-sponsored research project, Evaluation of Digital Alert Systems Associated with Emergency Response Vehicles and Compliance with Move Over Law:
https://doi.org/10.36501/0197-9191/26-003