Quad Day to benefit from CEE research collaboration

When 20,000 students descend on the University of Illinois Main Quad at the start of each academic year to learn about the myriad opportunities to get involved on campus, the crowds are understandably dense. Help is on the way though, thanks to a project involving CEE researchers and personnel from the University’s Facilities and Services unit (F&S) that promises to ease congestion and improve safety.

The project is the result of a collaboration between CEE structures assistant professor X. Shelly Zhang (BS 12, MS 14), also a CEE alumna; transportation professor Yanfeng Ouyang; and their respective graduate students Weichen Li and Ruifeng She. Ouyang has research interests in pedestrian behavior and traffic modeling, and Zhang specializes in a mathematical and computational method to optimize the shape and improve the performance of systems called topology optimization. Searching for campus events that could benefit from improvements to pedestrian traffic control, the two thought of Quad Day, scheduled for August 23, 2020, and Spring Jam, an annual concert on the Main Quad planned for spring 2021. F&S personnel welcomed the idea.

“We want to increase our academic collaborations and create more opportunities to make campus a living/learning lab, where researchers can implement projects and F&S can assist with resources – locations, equipment, material, staff time,” said Stacey DeLorenzo, F&S Transportation Demand Management Coordinator.

The project represents a unique integration of transportation engineering and topology optimization. Blending knowledge from their areas of expertise, the research team will develop a series of models and computational methods that aim to optimize the layout of displays and activities, as well as guideways and barriers, so as to channel pedestrian traffic to avoid gridlock. They’ll analyze the model results, observe field experiments and fine-tune their models.

“Usually topology optimization is to optimize for the layout of a structure and the governing principle is mechanics – for example, how the load is distributing in a structure,” Zhang said. “This case is a very innovative collaboration, because we are not considering mechanics, we are considering the physics of people’s travel behavior, so it’s quite interesting. The model accounts for how people behave under congestion. Quad Day is a perfect example, because it’s congested all the time, especially during the peak hours. A main challenge is to build an efficient computational framework to optimize the layout considering pedestrians’ behavior.”

Incorporating information into the model to reflect pedestrians’ behavior is another particular challenge.

“In transportation, we study how people choose their paths of travel, usually in predefined networks,” Ouyang said. “We now build models to describe how people make decisions when they can travel arbitrarily in an open area, and when their decisions influence the travel experience of their peers through congestion. Based on game theory – people consider the pros and cons of all their options and simultaneously seek the best for themselves -- we come up with the behavioral model whose mathematical form mimics those seen in mechanics.”

DeLorenzo and her colleagues at F&S see several advantages to better pedestrian traffic management.

“The primary goal of this research is to help optimize pedestrian traffic during Quad Day so the attendees can get to all the places and tables they want to visit within a reasonable timeframe,” DeLorenzo said. “In addition, this improves the safety of attendees and exhibitors.”

Ouyang is the George Krambles Endowed Professor in Rail and Public Transit.