The introduction of ride-sharing services such as Uber and Lyft hasn't had any impact on the number of fatalities related to drunken driving, a newly published study finds.
Researchers at the University of Southern California and Oxford University looked at the 100 most populated metropolitan areas, analyzing data from before and after the introduction of Uber and its competitors, and found that access to ride-sharing apps had no effect on traffic fatalities related to drinking alcohol.
Uber has repeatedly pointed to drunken-driving reduction as a benefit of its service. A 2015 blog post on its website, titled "Making Our Roads Safer For Everyone," notes a survey Uber conducted with the group Mothers Against Drunk Driving that found anecdotal evidence that people believe their friends are less likely to drive drunk since the introduction of Uber.
In June, a report by researchers at Providence College and Stonehill College found a reduction in fatal vehicle crashes associated with ride-sharing app availability.
Uber has also held up a 2015 study by data scientists at Temple University that showed a correlation between decreased alcohol-related driving fatalities, and the introduction of Uber services in California. The authors of that study, Brad Greenwood and Sunil Wattal, say they examined data from only one state and did not control for other factors that could effect drunken driving, such as changes in legislation. "Further work is necessary to ensure that there are not confounding factors which also influence the findings," they wrote in the paper's conclusion.
In latest study, published in the American Journal of Epidemiology, the researchers analyzed county-level data from 100 metropolitan areas in dozens of states, and controlled for the effects of state laws that could affect drunk driving fatalities, such as bans on texting while driving, marijuana-related legislation and taxes on alcohol.
The authors also separated total alcohol-related traffic fatalities from those that occurred on weekends or holidays, and found no reduction in deaths with the introduction of Uber in either case.
So, why? The authors of the study speculated that drunk people might not want to shell out for the services:
"The average inebriated individual contemplating drunk
driving may not be sufficiently rational to substitute drinking and
driving for a presumably safer Uber ride; it is also possible that
many drunk drivers rationally conclude that it is too costly to pay
for an Uber ride (or taxi) given that the likelihood of getting arrested for drinking and driving is actually quite low."
In response to the latest study, Uber spokeswoman Brooke Anderson told The Washington Post in an email:
"We're glad Uber can provide an alternative to drunk driving and help people make more responsible choices. Our ridership numbers show that trips peak at times when people are more likely to be out drinking and 80% of riders says that Uber has helped them personally avoid drinking and driving."
The Post quotes one of the study's authors, David Kirk, as saying: "The takeaway for me is that there's still tons of room for improvement when it comes to reducing drunk driving fatalities."