The relationship between declining DUIs and ride-hailing services isn’t as cut and dried as you might think.
Anyone who has been out on Brady Street past 10 p.m. on the weekend has seen the droves of inebriated young adults pouring in and out of Ubers and Lyfts. It seems common sense, then, that these ride-hailing apps are preventing drunken driving, right?
Not so fast, experts say.
Some studies have found positive changes in places after ride apps begin service. A 2018 study out of Western Carolina University analyzed national data and estimated a 0.8 percent decrease in DUI arrests for each additional month after these services are introduced. It also noted a decrease in fatal alcohol-related crashes and an increase in vehicle theft. (The best explanation offered for the bump in larceny is that Uberers leave more cars parked overnight in unsecure locations.)
“No matter what county we looked at, the introduction of Uber led to less drunk driving arrests,” says Sean Mulholland, who conducted the study. “And the longer Uber was there, the less DUI arrests there were as people became more acclimated to using their services – as was our hypothesis.”
Mulholland’s study roughly tracks Uber’s own reports. It claims that its introduction led to a 10 percent decrease in DUI arrests in some cities. In surveys, 78 percent of Uber users have said that it has helped them avoid drunk driving.
However, Marquette University social data scientist Shion Guha, an assistant professor of computer science, warns against assuming causation from the correlation between decreases in DUI arrests and the introduction of ride-hailing, especially in a city like Milwaukee. It’s a tempting jump to make, because the raw numbers are remarkable. Drunken driving arrests dropped 18 percent in 2014, the first year Uber and Lyft began service here, and the 2,183 arrests in 2017 was down more than 40 percent from the 2013, pre-app number.
“Given the data, and since ride-sharing has only been here for four years, it’s not possible to say anything about trends,” Guha says. “And there are dozens of confounding variables influencing this data that are impossible to control for.”
One of those is the fact that in the past few years, many young people are driving less because they are living in the city and opting for public transportation instead of car ownership. Another is how the city and county are policing drunk driving. DUI arrests, Guha says, often happen via checkpoints, which are harder to implement in the city, and Milwaukee’s drinking culture may yield less stringent enforcement. And the list of variables goes on.
The Milwaukee Police Department sides with Guha, saying it could not explain the big drop in drunken driving arrests since the apps’ debut and noting that police are still arresting large numbers of drunk drivers, especially on city freeways. MPD Sgt. Sheronda Grant also notes that distracted driving is a big issue that’s exacerbated by the maps and alerts directed to Uber and Lyft drivers.
At this point, it should be noted that data scientists like Guha are extraordinarily cautious when it comes to declaring that data correlation is due to causation.
“This is an area where the public perception conflicts with the data,” Guha says. “We don’t have all the answers yet, so we’ll have to wait a few years for more data to make any causal claims.”
Drunk in Wisconsin — By the numbers
Wisconsin is a notoriously bad state for drunken driving. In a 2018 study by carinsurance.com, it ranked as the deadliest state for drunken driving while having the third-most-lenient penalties. — Jamie Price
SOURCE: Wisconsin Department of Transportation, Centers for Disease Control and Prevention
DUI Arrests in Milwaukee County
Although there has been a significant dip in DUI arrests since ride-sharing services were introduced to the county in 2014, data scientists argue that there isn’t enough data yet to declare a trend.
SOURCE: Wisconsin Department of Justice