The advent of smart-phone based, ride-sharing applications has revolutionized the vehicle for hire market. Advocates point to the ease of use, lower prices, and shorter wait times compared to hailing a taxi or pre-arranging limousine service. Others argue that proper government oversight is necessary to protect ride-share passengers from driver error or vehicle parts failures and violence from unlicensed strangers. Using U.S. county-level data from 2007 through 2015, we investigate whether the introduction of the ride-sharing service, Uber, is associated with changes in fatal vehicle crashes and crime. We find that Uber’s entry lowers the rate of DUIs and fatal accidents. For some specifications, we also find declines in arrests for assault and disorderly conduct. Conversely, we observe an increase in vehicle thefts.