Alcohol-impaired driving fatalities

As New Yorkers have taken more Citi Bike trips, alcohol-impaired driving fatalities nationwide have increased, a correlation that suggests either that bike-sharing inspires drunk driving or that the same post-pandemic economy that put people back on bikes also put people back behind the wheel with a cocktail. The coefficient is 0.864 across ten years, during which both metrics rose, crashed in 2020, and recovered with the resilience of activities that require leaving the house after dark.

Citi Bike trips grew from about 6 million in its 2013 launch year to over 30 million by 2022, driven by station expansion, e-bike introduction, and post-pandemic transit aversion. Drunk driving fatalities grew from about 10,100 to over 13,300 nationally, reversing years of progress. Both trends share a pandemic-shaped curve: collapsing in 2020 and rebounding strongly afterward. The shared variable is not alcohol or bicycles but mobility—when people move around more, more of them ride Citi Bikes and more of them drive drunk. The pandemic suppressed both and the recovery amplified both, creating a correlation that is largely a pandemic artifact.

Ten years of Citi Bike and drunk driving is a correlation sculpted almost entirely by the pandemic dip and recovery. When Americans stopped moving, both metrics collapsed; when they started again, both surged. The rides resumed, the driving resumed, and the drinking never really stopped. The correlation is just mobility, measured from two angles.