New ASU research examines how varying COVID-19 'shelter in place' policies influenced travel

At the beginning of 2020, as COVID-19 spread, schools, bars and gyms shuttered; nonessential travel was restricted; and cities around the world implemented their own unique protocols to slow new infections of the novel coronavirus. 

But how did the public respond? Did these policies have an effect on movement and travel? And how did patterns differ in cities around the world? 

Three Arizona State University researchers in the School of Geographical Sciences and Urban Planning sought to find out how people moved through their lives differently due to the pandemic. 

The new research, led by Sarbeswar Praharaj, assistant research professor with the Knowledge Exchange for Resilience and the School of Geographical Sciences and Urban Planning, uses a visual and data-driven lens to see how COVID-19 government policies have impacted public mobility. 

“We all know from our experience that mobility is severely impacted by the COVID-19 legislation and guidelines that are placed by local, subnational governments, and countries, but what we do not know is whether the stay-at-home, school closure and shutdown restrictions have impacted uniformly or contrastingly across global regions and regimes,” Praharaj said.

“A better understanding of community mobility is important because it indicates the level of social distancing in cities. Data-driven insights can assist operationally and strategically to plan more resilient cities as we continue to tackle the COVID-19 pandemic and beyond.” 

A visual and data-driven approach

Using daily trip request data from Apple Maps captured over the course of the year, Praharaj and his team visualized the rapidly changing mobility patterns across the metro regions of London, Phoenix, Sydney and Pune, India, before, during and after “lockdown” policies were implemented and lifted.   

The team of researchers — which includes David King, assistant professor in the School of Geographical Sciences and Urban Planning; Elizabeth Wentz, interim director and professor in the School of Geographical Sciences and Urban Planning; and Christopher Pettit, University of New South Wales — developed a robust statistical model to test whether patterns significantly varied across these global cities, which have a different timeline of COVID-19-related policy events.

“Researchers — and planners and policymakers alike — need to understand as many facets of the pandemic as possible. This includes aspects of the disease, transmission, rates, prevention and its impacts,” said Wentz, co-author of the paper. “In this case, we look at how changes in broad policies affect individual decision-making. We see those outcomes in terms of different modes of transportation and the changes to mobility with respect to different key moments in time.”

Similar policies, different response  

The study found that while mobility went down substantially across all four cities immediately after COVID-19 was declared a global pandemic by the World Health Organization and the subsequent local-level social distancing rules were enforced, once local stay-at-home policies were lifted, cities responded quite differently across the globe. 

For example, in Phoenix, driving and public transit trips fell 60–70% below average by mid-April. At the same time, London experienced a massive 90% reduction in public transit trip requests. 

But after lockdown interventions were lifted, mobility in Phoenix and Sydney surged, while London and Pune saw insignificant upward change on trip requests over Apple Maps, suggesting there was a large number of people still working from home and avoiding nonessential travel. 

“Our findings reflect the global nature of the pandemic and the local nature of policy responses,” Praharaj said. “The article provides insights into how a same set of policies can receive a starkly varied response from communities across global regions and highlights the power and significance of messaging by the governments in dealing with a humanitarian crisis.” 

In future research, Praharaj and his team aim to expand on the Apple Maps data with other data sources to dive more deeply into people's specific travel destinations to get a better sense of where in the metropolitan areas things changed. 

“By looking at restaurants, theaters, hospitals, schools and other types of destinations, we can get a better sense both spatially and temporally across time as to how people's behavior changed as the pandemic came rolling through,” said King, co-author of the study. “Ideally, we'll be able to look at a lot of cities, then within cities be able to see if it was the denser parts of town that responded differently than the exurban parts of the city or whatever it might be.” 

Local research with a global impact 

The international study was ideated through research being done for Arizona communities through ASU’s Knowledge Exchange for Resilience’s Mobility Disruptions Dashboard. 

“We have been continuously tracking how COVID-19 is rapidly transforming the community mobility behavior in Arizona counties and Phoenix metro over the last eight months,” Praharaj said. “We were interested in sharing the knowledge gained at ASU with PLuS Alliance researchers, and to apply the data analytics tools we have built on other cities across four continents to uncover the impacts of the COVID-19 pandemic.” 

The PLuS Alliance initiative is a research collaboration between ASU, King’s College London and University of New South Wales, Sydney, created to accelerate global scholarship and share knowledge between universities to solve pressing educational and societal challenges. 

“This article is a spin-off product from the project providing an easy-to-use and reliable approach and tool to compare cities globally to assist policymakers in planning better and more sustainable and resilient cities and regions,” Praharaj said.

“While we at the ASU School of Geographical Sciences and Urban Planning and the Knowledge Exchange for Resilience are doing research that is locally grounded, it also has a strong global impact.” 

Read the full paper, available for download and open access.