Not only have there not been any deaths in Citi Bike’s five-month existence (as the New York Times glibly claimed), according to Esri engineer Tom Swanson, Citi Bike hasn’t substantially increased the instance of non-fatal bike accidents either.

Using data from the NYPD Motor Collision Data Reports, Swanson aggregated accidents in which bikes were since August 2011. The result of that data collection can be seen in the graph below.


Swanson’s conclusion? “Based on the collision data published by the NYPD, and more importantly on the last 4 months of data since the launch of the bike share program by Citi Bike, my analysis shows that there is no significant increase to bike collisions in the areas with Citi Bike docking stations compared to all bike collisions in the city.”

So, despite the data displaying a slight uptick in accidents between 2011/2012 (no Citi Bike) and 2013 (Citi Bike), the percentage increase is small and “consistent with historical percentages.” Thus, not only has no one died using Citi Bike, the program hasn’t increased the number of bike accidents beyond what would be considered normal with or without the bike share program.

And not only did Swanson develop a chronology of bike accidents, he also created a heat map that displays where bike accidents are occurring. Among the practical implications that a map like this offers, planners and city officials can pinpoint problem areas and examine ways to make those areas safer by investing in better infrastructure or implementing new policy.


A screenshot of Swanson’s heat map. View the interactive map via the link in the text above.