  Mobility interventions in communities play a critical role in containing a
pandemic at an early stage. The real-world practice of social distancing can
enlighten policymakers and help them implement more efficient and effective
control measures. A lack of such research using real-world observations
initiates this article. We analyzed the social distancing performance of 66,149
census tracts from 3,142 counties in the United States with a specific focus on
income profile. Six daily mobility metrics, including a social distancing
index, stay-at-home percentage, miles traveled per person, trip rate, work trip
rate, and non-work trip rate, were produced for each census tract using the
location data from over 100 million anonymous devices on a monthly basis. Each
mobility metric was further tabulated by three perspectives of social
distancing performance: "best performance", "effort", and "consistency". We
found that for all 18 indicators, high-income communities demonstrated better
social distancing performance. Such disparities between communities of
different income levels are presented in detail in this article. The
comparisons across scenarios also raise other concerns for low-income
communities, such as employment status, working conditions, and accessibility
to basic needs. This article lays out a series of facts extracted from
real-world data and offers compelling perspectives for future discussions.
