As Gov. Jared Polis’s shelter-in-place order takes effect on Thursday morning, a new analysis of social distancing practices has found that Coloradans have reduced their daily distance traveled by 37% since late February.

Unacast, a New York-based company that collects mobility data through tracking cell phones, originally attempted to explore “activity clusters” and people’s average time dwelling in their homes as a result of the coronavirus pandemic. However, they decided to focus solely on the change in average distance traveled because the signals from cell phones were most reliable with movement.

“The metric correlates well with the number of confirmed cases: the more cases are confirmed, the greater the decrease in the average distance traveled on the county level,” Unacast explained.

In Denver, distances traveled shrunk by 53%, while El Paso County residents were 36% less mobile. Eastern Plains counties had the least change in behavior, with several counties actually seeing residents travel farther as the pandemic progressed. Nationally, the regions that experienced the largest contractions in travel distance were the Northeast, the upper Midwest and the West Coast. 

Wyoming was the state in which mobility changed the least. Its governor has not yet issued a shelter-in-place order, but has urged residents to work from home and warned that the state’s rural profile “does not protect us” from COVID-19.

As employers lay off their workforces or switch to teleworking and as events worldwide get canceled, people have become less mobile to prevent the spread of the virus. Unacast cautioned that traveling small distances does not necessarily mean avoidance of crowds. The company will next try to evaluate the number of encounters a person may make or the number of locations visited aside from a dwelling.

The data Unacast relies on do not have personal identifiers attached and come from location-enabled tracking on smartphones. Science magazine reports that governments are exploring location tracking as a method to combat the pandemic, potentially by “contact tracing” infected persons and alerting other cell phones in the vicinity about potential exposure.

A recent survey from Morning Consult found that a majority of Americans would oppose government tracking, even if it were part of the pandemic response.