InTrans / Apr 11, 2018

InTrans works with Iowa DOT to improve work zone safety

Monday marked the beginning of work zone safety awareness week.

But for engineers at Iowa State University’s Institute for Transportation (InTrans) and staff at the Iowa Department of Transportation (DOT), work zone safety awareness is never-ending. Literally.

Traffic sensors and cameras are set at specific locations along key traffic critical projects to monitor work zones 24-7.

InTrans collects data from those sensors and cameras every 20 seconds, and then machine learning and algorithms are able to pull out usable information that alerts key personnel at the Iowa DOT to any traffic slow-downs.

Plus, the data gets posted to InTrans’ REACTOR Lab website, so engineers and contractors can monitor traffic patterns weekly, daily, and over time, to see how the critical work zones are performing.

“This is just providing the eyes and ears that are always watching and listening,” said Skylar Knickerbocker, a research engineer with the REACTOR Lab, who oversees the data collection and management for Iowa’s Intelligent Work Zone (IWZ) program.

The number of sensors and cameras vary per project, but on average the sensors are placed a mile apart. Iowa is currently monitoring 24 traffic critical work zone sites.

The recent advances in technology have allowed for the collection and interpretation of data, and over the last three years, InTrans has refined both to provide better insights into what’s happening in work zones across the state. The number of performance measures have been refined, but one of the most accessed is the speed heat map, which is a graphical tool that color-codes the travel speed over a period of time to highlight when slow-downs occur.

Knickerbocker said text alerts, a resource added in 2017, notify DOT engineers sooner when traffic stops for longer than five minutes. The text message is automatic and comes with an image to show the extent of the back up, so the DOT is aware of an issue immediately rather than learning of it when a call comes in about the congestion.

Knickerbocker and Neal Hawkins, associate director of InTrans and REACTOR Lab, make clear their role is to collect and analyze the data, rather than make decisions for the Iowa DOT.

“We’re not telling them what to do. We’re telling them there’s something going on here, so that they are aware of it as soon as possible,” Hawkins said.

But the information alone has proven valuable.

“Safety in work zones is always our focus at the Iowa DOT, and the text message alerts and traffic performance data provided by InTrans have been game-changing tools. InTrans is able to take massive amounts of sensor data and boil it down to specific, instant and useful information about traffic issues in our work zones. That information allows us to take appropriate and immediate action to make our work zones more safe and efficient,” said Tim Simodynes, the Iowa DOT’s intelligent transportation systems engineer.

Knickerbocker also notes that past practice — before establishing more immediate access to the data — would have been to provide work zone traffic information in an annual report. If there were traffic problems identified in the annual report, it was too late to implement any mitigation strategies because most of the construction projects were finished at that point.

The current data analytics on traffic critical projects, on the other hand, gives performance measures on a regular basis so the Iowa DOT can make traffic control changes, or even deploy automated queue detection and warning systems, while the work zone efforts are ongoing.