Flagging down a competition victory
Two teams of Mizzou students completed a clean sweep of the top two spots at the recent Central Missouri Institute of Transportation Engineers-sponsored Poster Session at Missouri’s 2017 Highway Safety and Traffic Blueprint Conference.
MU Civil Engineering graduate students Zhu Qing and Siyang Zhang earned first-place honors for their poster, “Evaluation of Automated Flagger Assistance Devices in Missouri,” while fellow grad students Nipjyoti Bharadwaj and Yohan Chang finished second with “Understanding the Impacts of Work Zone Activities on Traffic Flow Characteristics.”
Qing and Zhang’s winning project utilized automated flagger assistance devices (AFADs) developed by the Missouri Department of Transportation — the project’s sponsor — in an attempt to see just how well drivers respond to the automated system rather than an actual human flagger when driving through work zones. AFADs utilize Stop/Slow paddles, a red and yellow beacon and a changeable message sign (CMS), all mounted on a truck mounted attenuator (TMA) and operated by a human flagger.
“That’s risky for them to stand in immediate traffic. Could we use machines to replace humans to save lives and improve the work zone safety?” Zhang said.
What the duo found was that in a driving simulator study, drivers responded to the virtual version of the flagger in a manner that saw them reduce their average approach speeds by more than 7.7 miles per hour while increasing the distance over which they slowed to a stop by at least 24 feet.
In the field study, the AFAD slowed approach speeds by more than 4 miles per hour, stopped vehicles more than 11 feet farther back from the construction site and released traffic more quickly than a standard human flagger.
Surveys were given to drivers in both groups, and results showed that drivers generally understood the directions of the AFAD and showed a preference for AFADs over human flaggers. The ease of use coupled with increased safety for both drivers and workers could lead to greater deployment of such devices in the future.
“The drivers understand the device reasonably well. Based on these measures, we can suggest that using AFADs can improve work zone and worker safety. ” Qing said.