It’s been 40 years since Britain enforced a legal limit of alcohol behind the wheel – but drink driving still took 220 lives in 2015.
One company trying to reduce this statistic is Uber, which is quite confident in its ability to lower alcohol-related road fatalities. It describes itself as a “powerful tool in the quest to protect families from drunk driving”, and has cited research backing this up in a number of major cities.
But while the intention is commendable, the data is not so conclusive. A study published earlier this year did find a 25 to 35 per cent reduction in alcohol-related car accidents in New York, following Uber’s arrival in 2011. Research from 2016, however, analysed data from the US’s 100 most populated metropolitan areas, and found Uber made no difference to traffic fatalities, including those involving alcohol.
So what explains the disparity? According to new research, it may come down to the design of individual cities.
Researchers from the Perelman School of Medicine at the University of Pennsylvania zoomed in on for US cities where Uber services had ceased then been reintroduced. Analysing data from state Departments of Transportation, they found a 29 per cent decrease in alcohol-involved crashes in San Antonio and a 62 per cent decrease in Portland, but in Reno there was no noticeable change.
The study, published in the American Journal of Epidemiology, concludes that the impact of Uber on drink driving-related crashes could depend on a city's characteristics, and how much they discourage people from driving. A city with more congestion and limited parking, for example, may see a greater difference once Uber comes along.
“Theoretically, ridesharing could reduce alcohol-involved crashes in locations where other modes of transportation are less attractive than driving one’s own vehicle while under the influence of alcohol,” the study states.
That said, this theory doesn’t explain the decrease in crashes in San Antonio, where public transport is scarce and most people rely on cars. And there are other factors at play, too. Disparities between cities may also be down to the willingness of locals to use other transportation, how expensive Uber fares are compared to the alternatives, even media attention and public interest in Uber. The study adds that, “The perceived attractiveness of ridesharing will depend, among other things, on a city’s topology and the strength and enforcement of drunk-driving laws.”
Despite the decrease in alcohol-involved crashes in Portland, there study found no changes to crashes with injury overall. “In our analyses the reductions in alcohol-involved crashes due to ridesharing were wholly offset by increases in non-alcohol crashes,” explains Christopher Morrison, the study’s lead researcher. “So it is possible that ridesharing doesn’t affect the overall number of crashes in a city.”
What might cause these non-alcohol crashes? The paper states that rideshare drivers have to use a mobile phone when driving, which could cause “distraction in the form of glances away from the road,” subsequently increasing the risk of crashing.
But, Morrison adds, “Alcohol-involved crashes typically occur at higher speed and are more serious than non-alcohol crashes. So the benefits may still outweigh the costs.”