Exchange Street was virtually empty on April 6, 2020 as social distancing due to the COVID-19 outbreak significantly reduced traffic in downtown Bangor.

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About 40 percent of Maine residents have stayed home completely on any given day over the past few weeks, according to new cell phone data that offer a glimpse into how much residents are socially distancing in response to the coronavirus pandemic.

The new cell phone data show that Maine residents were already staying at home more before Gov. Janet Mills formally issued a stay-at-home order at the end of March, and compliance with social distancing measures has remained high through the first few weeks of April.

[Our COVID-19 tracker contains the most recent information on Maine cases by county]

While social distancing remains the primary tool to prevent the spread of the virus, state agencies and epidemiologists, including the Maine Center for Disease Control and Prevention, have looked at cell phone data as one proxy for measuring the extent to which individuals are complying with official restrictions.

The rate of new hospitalizations due to coronavirus declined last week, a potentially positive sign, but public health experts still say that removing restrictions right now would risk another spike in cases. As of Wednesday, there were 907 confirmed coronavirus cases in Maine, including 413 current cases as well as 39 deaths.

One way for Mainers to comply with current guidelines is to stay in their homes all day. An analysis by the firm SafeGraph measured what share of residents, both in Maine and across the U.S., went all day without leaving their homes, based on a cell phone data measured with a precision of roughly 100 square meters.

In Maine, approximately 40 percent of residents who have stayed home completely on any given day over the past few weeks, representing a significant increase from a baseline of between 20 and 25 percent in early March.

The percentage of Mainers staying home each day grew steadily to around 35 percent after the state’s first coronavirus case was announced on March 12, aligning with previous data showing that travel in Maine plummeted once the virus was confirmed in the state. The figure rose to its current level after Mills issued a formal stay-at-home order on March 31.

The Maine counties hit hardest by the coronavirus also saw more residents staying home than their counterparts with fewer confirmed cases. In Cumberland and York counties, which accounted for about 64 percent of confirmed cases of the virus in Maine as of Wednesday, the share of residents staying home each day was closer to 44 percent.

Maine falls a bit behind the national average when it comes to staying home. The data show that, across the U.S., about 44 percent of people have stayed home all day over the past few weeks. Several of the states hit hardest by coronavirus, including New Jersey and New York, ranked highest, with around 51 percent of residents staying home all day each day.

A second report using cell phone data, released by Google earlier this month, hints at where Mainers are going when they do leave their homes. In the weeks after the first coronavirus case was confirmed in Maine, daily travel to retail stores and workplaces dropped by roughly one-third compared to a February baseline, the data show.

Travel to grocery stores did not initially drop when coronavirus was first confirmed in Maine, but did after Mills’ stay-at-home order. Over the first two weeks of April, travel to grocery stores was down 17 percent from a February baseline, while travel to other places was down nearly 50 percent.

Public health officials have generally cautioned that it takes several weeks to see the effects of social distancing measures. But, three weeks after Mills’ stay-at-home order, several models, including one developed by researchers at the University of Washington, suggest that Maine’s social distancing efforts have effectively “flattened the curve” and that cases will decline if the current measures continue for several more weeks.

However, officials have also warned that resuming normal activities too early could lead to a resurgence in cases. Maine CDC Director Nirav Shah said on Wednesday that the agency was studying current case counts as it considers when it might be safe for the state to lift some restrictions.