A real jam: ICT-IDOT improving your commute one stoplight at a time

Workweek traffic often feels like a rat race. Horns beeping, road-rage drivers, you name it. We’re all just trying to make it through the stoplight to punch in on time.

Time spent in traffic is nothing short of alarming. In fact, Chicagoans on average spent 57 hours a week in peak traffic in 2017, according to Statista.

Traffic backs up along Neil Street following an event at Champaign’s State Farm Center during testing of a real-time adaptive traffic control system.

That’s something Illinois Center for Transportation and Illinois Department of Transportation wanted to change with joint research project “R27-127: Evaluation of Adaptive Signal Control Technology.”

Coordinating stoplights is by no means new, according to Kyle Armstrong, IDOT’s engineer of traffic operations, who also served as the project’s technical review panel chair.

“For many years, that coordination typically involved developing timing programs ahead of time, and then running those programs at certain times of the day,” he said. “So you might have a program to handle the morning rush hour, another program to handle the afternoon rush hour, then maybe another program to handle the noon hour and other times when traffic isn’t quite as heavy.”

While pre-timed traffic signals work well for some occasions, other times — like event traffic — they’re not much help.

New adaptive signal control technology, on the other hand, promises a more streamlined approach, adjusting stoplights based on traffic volume.

“It’s constantly monitoring the amount of traffic that’s within the corridor, and it can make adjustments to the preprogrammed coordinated timing programs and automatically implement programs based on what it is actually detecting or seeing,” Armstrong said. “Ultimately, it’s providing a lot more flexibility.”

Researchers decided to put a real-time adaptive traffic control system to the test following a competitive bidding process based on the Illinois Procurement Code.

The question became: Where should the researchers test such cutting-edge technology?

Researchers tested a real-time adaptive traffic control system along six heavily traveled Neil Street intersections, including Devonshire Drive, Kirby Avenue, Knollwood Drive, St. Mary’s Road, Stadium Drive, State Street and Windsor Road.

After careful consideration, University of Illinois Urbana-Champaign Department of Civil and Environmental Engineering Professor Rahim Benekohal, who served as the project investigator for the joint research effort, looked no further than Champaign’s Neil Street corridor.

Here researchers implemented the adaptive signal control technology along six intersections of this major street nestled into UIUC campus’ western edge.

“We wanted to have a corridor that was prone to seeing some sudden and rapid increase in traffic,” Armstrong said.

The four-year project took a closer look at traffic volumes, delays, queue lengths, signal timing and much more using traffic cameras at the six intersections.

Traffic flow lags at the intersection of Neil Street and Kirby Avenue during implementation of a real-time adaptive traffic control system.

Researchers concluded timed signals are the most efficient approach for urban towns like Champaign-Urbana, but adaptive systems certainly show potential to optimize traffic flow in other areas.

Perhaps the biggest takeaway from the project was the researchers’ methodology — systems engineering analysis.

“It’s basically taking an inventory of the signals and corridors and determining what you have, and also determining what features you want the adaptive system to be able to control,” Armstrong said.

This methodology will serve as a “template” to help others implement adaptive systems thanks to ICT and IDOT’s joint effort.

Check out the project’s reports, which are as follows:

Posted: July 30, 2019

Written by: Emily Jankauski