LISTEN: I-85 collapse provides Tien a test case of infrastructure interdependence

Assistant Professor Iris Tien, center, with WABE-FM's Jim Burress and Rose Scott after their conversation about Atlanta's infrastructure on the station's daily program Closer Look. (Photo Courtesy: WABE)
Assistant Professor Iris Tien, center, with WABE-FM's Jim Burress and Rose Scott after their conversation about Atlanta's infrastructure on the station's daily program Closer Look. (Photo Courtesy: WABE)
 

For a researcher who studies the ways society’s infrastructure systems are interconnected and interdependent, the Interstate 85 collapse this spring in Atlanta had a silver lining.

School of Civil and Environmental Engineering Assistant Professor Iris Tien told Atlanta public radio station WABE that shutting down one of the city’s main thoroughfares presented a rare opportunity — despite the disruption to businesses and the extra travel time for residents.

“In our research, we look at infrastructure as a network, an integrated system with different moving parts and different individual components that might affect overall network performance. And so, the I-85 collapse was almost like a test case for some of our research models,” Tien told Rose Scott and Jim Burress on Closer Look.

“In our models, we might say, if we take away one of these critical links of our infrastructure, how does the rest of the system adapt … to meet that new situation? And here we had a real-life case where we could see what happens exactly when you remove one link from the infrastructure and see how the effects cascade across the entire network.”

Tien said the I-85 experience showed metro Atlantans are adaptable. But it also raised questions about how we design our infrastructure to handle major disruptions.

“How do you design transportation networks? Where do you build these redundancies? How do you have alternative routes?”

Having local roads available to reroute I-85 traffic helped, Tien said, “But they also raised, from a research point of view, questions about where in the system do you want to build these redundancies and where is the most critical part to build [them]?”

Tien is involved in projects right now with the City of Atlanta Office of Emergency Preparedness and the Georgia Department of Transportation to evaluate the impact of the I-85 collapse and closure. Her findings will ultimately lead to recommendations about how to design infrastructure systems.

Overall, Tien said she feels optimistic about the region’s infrastructure, pointing to the city of Atlanta’s involvement in the Rockefeller Foundation’s 100 Resilient Cities project as one way local leaders are looking for new ideas. (Tien helps lead one of the initiative’s groups working on strengthening and maintaining infrastructure and promoting community preparedness.)

And even though Atlantans saw a portion of another interstate highway shut down from buckling and a Midtown Atlanta street closed from a sinkhole shortly after the I-85 collapse, Tien said there’s no overarching theme of a region falling apart.

“Another part of my research [deals] with uncertainty and risk and trying to quantify uncertainty,” she said. “For both of these cases, they were low-probability, high-impact events that just happened to happen in very close proximity to each other. I think that affected the [public] perception.”

In fact, Tien said the closure of I-85 reminded people how much they depend on infrastructure systems every day.

“It shed light on infrastructure that might not normally get the attention it might deserve.”