Ridesharing and Motor Vehicle Crashes in 4 US Cities: An Interrupted Time-Series Analysis

In the American Journal of Epidemiology, Christopher Morrison and colleagues, including Sara Jacoby, M. Kit Delgado, and Douglas Wiebe, investigated if ridesharing, specifically if using Uber, reduces the rate of motor vehicle crashes.

The authors conducted an interrupted time series analyses using weekly counts of injury crashes and the proportion that were alcohol-involved in four US cities where Uber had piloted, abruptly ceased operations, and then abruptly resumed (Las Vegas, NV; Portland, OR; Reno, NV; San Antonio, TX). The authors hypothesized that Uber’s resumption would be associated with fewer alcohol-involved crashes.

Results partially supported this hypothesis. For example, in Portland, Uber’s resumption was associated with a 61.8 percent reduction in the alcohol-involved crash rate (an absolute decrease of 3.1 alcohol-involved crashes per week), yet there was no associated change in all injury crashes. The study suggests that ridesharing may affect motor vehicle crashes, particularly alcohol-involved crashes, but that relationships are likely to differ across geographic settings and over time.