Although Minnesotans drove significantly less in 2020 due to the COVID-19 pandemic, there was a substantial increase in fatal motor vehicle crashes. MnDOT Traffic Safety Engineer Derek Leuer and his colleagues want to know why, particularly in rural areas where fatalities and injury rates were higher.Continue reading New Project: COVID-19 Impacts on Speed and Safety for Rural Roads and Work Zones
When drivers approach a roadway work zone at high speeds, they put the lives of work-zone flaggers at risk. To keep flaggers safe on the job, U of M researchers are looking for better ways to capture drivers’ attention—and compel them to slow down—as they approach flagger-controlled work zones.
Kathleen Harder, director of the Center for Design in Health, and John Hourdos, director of the Minnesota Traffic Observatory, identified and tested new work-zone warning elements to more effectively capture and sustain driver attention. The project was funded by MnDOT and the Minnesota Local Road Research Board.
The project began with a simulator study in which participants completed three drives, each featuring a work zone with different warning treatments. One condition was a traditional four-sign configuration currently used to warn drivers approaching work zones. The other two conditions featured a variety of new elements, including signage with new messaging such as a “one-lane road ahead” sign with flashing LED lights, a dynamic speed warning sign equipped with a loud warning horn that sounded if drivers exceeded the speed limit, and portable rumble strips.
“Overall, we found that the new set of elements is more effective than the elements currently used to reduce driving speeds on the approach to a flagger-controlled work zone,” Harder says.
Although adding LED lights to the one-lane road sign had no significant effect on drivers’ speeds, findings indicated that the dynamic speed sign coupled with the horn was more effective than the dynamic sign alone.
To test these new elements under real-world conditions, the researchers conducted field tests evaluating two configurations in Minnesota work zones. The first configuration followed the minimum standards outlined in the Minnesota Manual on Uniform Traffic Control Devices. The second deployed signs employing new messaging and attention-getting devices, including a dynamic speed warning sign, horn, and rumble strips.
Findings showed that the combination of the dynamic speed warning sign and the horn successfully reduced the overall speed of vehicles approaching the work zone. The portable rumble strips did not cause any significant speed reduction, but this may have been related to their location downstream from the dynamic speed sign and horn.
“Our findings reveal that the new set of elements designed to capture driver attention—including new messaging, a dynamic speed trailer, and horn—had a significant influence on reducing driver speed,” Harder says. “The experimental layout practically eliminated high-speed outliers and successfully reduced the approach speed to the flag operator.”
The story aired as part of KARE 11’s #eyesUP campaign to end distracted driving.
The app works by pairing with Bluetooth low-energy tags placed in work zones, triggering audio warnings in smartphones that are within their range. This allows drivers to get a warning message without having to look down at their phones—or at warning devices such as changeable message signs outside their vehicles. And if a driver is being distracted by their phone, the app will interrupt whatever they are doing to provide a warning that a work zone is up ahead.
U of M researchers Chen-Fu Liao and Nichole Morris, who worked on the project, are interviewed in the story, along with Ken Johnson, work-zone, pavement marking, and traffic devices engineer at MnDOT.
Join us in person on the U of M campus or tune in online to the CTS winter research seminars. The seminars will highlight a sampling of the latest transportation research at the U of M.
Here’s this year’s seminar schedule:
- February 18, 2 p.m. — Flagger Operations: Investigating their Effectiveness in Capturing Driver Attention in Work Zones
- February 20, 10 a.m. — Determining Creep Compliance and Strength of Asphalt Mixtures at Low Temperatures
- February 25, 2 p.m. — Experiments on Culvert Design for Fish and Aquatic Organism Passage in Minnesota
- February 27, 10 a.m. — Statistical Analysis of Fare Compliance
Each seminar will be held in Room 50B at the Humphrey School of Public Affairs. Or, if you can’t make it in person, you can watch the seminars live online or view recordings posted after the events. For details about the live broadcasts, see the individual seminar web pages.
There’s no cost to attend, and each seminar qualifies for one Professional Development Hour.
Hope to see you there!
The Minnesota Local Road Research Board is a major source of funding for transportation research in the state. Occasionally, it also produces educational videos designed to raise public awareness of important transportation topics.
Two new video offerings from the LRRB (embedded above and below) are focused on save driving in work zones. While not directly research-related, they might prove a useful resource to transportation professionals. More importantly, they serve to remind us all of the very real and dramatic consequences of work zone crashes, of which there are approximately 2,000 per year in Minnesota.
You might want to also check out some of their other recent YouTube offerings, including explanations of why we need stop signs and speed limits, as well as a fascinating look at how potholes are patched.