"A new study casts doubt on Uber's claim that ride-sharing has reduced drunken driving," reports the Washington Post. An anonymous Slashdot reader quotes their report: Researchers at Oxford University and the University of Southern California who examined county-level data in the United States before and after the arrival of Uber and its competitors in those markets found that ride-sharing had no effect on drinking-related or holiday- and weekend-related fatalities. One reason could be that, despite the soaring popularity of Uber and other ride-sharing services, there still may not be enough ride-share drivers available yet to make a dent on drunken driving, the authors said.

They also suggest that the tipsy riders who now call Uber are the ones who formerly would have called a taxi. For others, the odds of getting a DUI are still so low that many would prefer to gamble rather than lay out money for a ride-sharing service. Drunks, after all, are just not rational.
One reason for the low number of Uber drivers may be that the 10-year study only examined data through 2014. While other studies have found a decrease in drunk driving arrests associated with Uber -- for example, in California -- the Post's article suggests that ridesharing drivers may just be a drop in the bucket. "Although approximately 450,000 people now drive for Uber, there are 210 million licensed drivers in the United States -- and an estimated 4.2 million adults who drive impaired, the study says."