With alarms sounding over people gathering in large groups for Thanksgiving, driving the spread of COVID-19 to new heights, there is some hope that people are traveling less.
One of the ways the University of Washington’s Institute of Health Metrics and Evaluation (IMHE) can make projections into the future of the pandemic is by watching how people move around through the use of cell phone data.
More movement means more spread. Less movement means there is less contact and fewer opportunities for the virus to infect others.
This chart from IMHE, although marked “Social Distancing,” is actually showing how much we’re moving in Washington. From late October to Nov. 10, cell phone data shows 29% less movement than in pre-pandemic January.
While that data is lagging by several weeks, new data from the Washington State Department of Transportation (WSDOT) suggests a similar trend, showing that vehicle traffic is dropping again. It's down 22% on average from where we were at this time in 2019.
The numbers are arrived at differently. WSDOT has counters embedded in the pavement. IMHE uses cell phone data that would also pick up people moving in cars.
“That is data that can track you and say how many people went to a place. That data on mobility is very good and very rich. You can see how much travel has happened, where people traveled to and so on,” said Dr. Ali Mukdad of IMHE. “Google could give you mobility of cell phones at airports. You can see how many people went to an airport.”
The data is not assigned to individuals, and is anonymous.
At the airport, the Transportation Security Administration has backed off projections from a week earlier that showed the peak Thanksgiving holiday travel days of this Wednesday and the following Sunday would be up by 45%.
Now, that increase is expected to be only about half that amount.
“The trend in mobility is coming down,” Mukdad said. But he knows well that if the travel numbers go up, as they have during other holidays during the pandemic, such as the Fourth of July – the number of infections, hospitalizations and deaths will also increase.