County residents' travel decreased overall soon after Montgomery County reported its first case of COVID-19 on March 10. However, mobility has picked back up over the past several weeks as businesses and other services have gradually opened, according to anonymous data collected from millions of smartphones by the New York-based information technology company Cuebiq.
One metric used to measure the distance traveled by smartphone users, Cuebiq's proprietary mobility index, showed a nearly 30% decline in Montgomery County residents' daily travel less than one month after the county's first COVID-19 case was confirmed. The mobility index is a measurement of the median distance traveled daily by all devices within a select area averaged over seven days, according to Cuebiq.
The index is presented on a scale of 1 to 5, with each whole number representing increased travel by a factor of 10. A mobility index of 1 shows median daily travel of 10 meters, while an index of 5 shows median daily travel of 100 kilometers.
Montgomery County's mobility index had hovered above 4.0 through the start of 2020—meaning county residents' median daily travel was consistently at least 10 kilometers—and was recorded at 4.09 on March 10. Mobility saw a swift decrease through the following weeks, dipping to just above 3.0—or median daily travel of 1 kilometer—by March 26. County mobility reached a low of 2.91 on April 5, according to Cuebiq's data.
Since then, daily travel has continued to increase. From April 5 to May 1, the first day of Gov. Greg Abbott's phased economic reopening plan, Cuebiq's mobility index jumped nearly 25%. Growth was slower but steady in May, with Montgomery County's index rising just over 6% by June 1.
A separate Cuebiq measurement, its shelter-in-place analysis, showed a similar pattern by tracing the percentage of county residents traveling certain distances from their home each day. The measurement is broken into brackets of users who stay at home, and those who travel less than 1 mile, 1-10 miles or more than 10 miles from home daily, averaged over one week. According to Cuebiq, travel from home was measured as movement more than 330 meters from a person's residence.
The number of residents staying home increased greatly in March and was accompanied by a decline in residents traveling more than 10 miles from home. Just 19% of county residents did not leave their homes March 10, a figure that rose to 43% by March 26. Cuebiq traced 43% of those in the county traveling more than 10 miles from home March 10, while 24% did March 26.
The percentage of county residents traveling shorter distances from home has held fairly steady this spring. The number of county residents traveling less than 1 mile from home rose from just 4% to 5% between March 10 and June 1, while the number of residents traveling 1-10 miles from home daily shrank from 35% to 32%.
Since the start of April, travel farther away from home has steadily picked up with more than one-third of county residents traveling over 10 miles from home by June 1. The 29% of residents remaining at home daily has decreased since a late March peak, although that figure still represents a more than 50% increase over the number of people remaining at home prior to the arrival of the coronavirus in Montgomery County.