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Does New York City’s Bike-Share Program Mean More Smushed Cyclists? See The Data

Nearly seven months after New York’s streets were flooded with bright blue bikes with novice riders, there have been no deaths. But what about accidents? These maps paint a picture of how (not) dangerous the bikes really are.

New York City’s massive bike-share program dropped thousands of bikes onto the city’s cramped and congested streets and allowed anyone with even the smallest sense of balance to pedal out in the streets with the cars. Five months in, the New York Times drolly proclaimed “No Riders Killed in First 5 Months of New York City Bike-Share Program,” as if violent death was something we should just accept for cyclists. But dying is one thing–what about just accidents, or injuries caused by reckless Citibikers?

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Nearly seven months after New Yorkers first took their heavy blue frames for a spin, Tom Swanson, a solutions engineer for the mapping firm Esri and an avid cyclist, has crunched the numbers. By his count, Citibike has actually not significantly increased the number of bike collisions at all.

A 3-D heat map of the bike collision density.

Swanson scraped his data from NYPD Motor Collision Data reports, then mapped the events using an intersection tool he developed for the New York City Office of Emergency Management in the wake of Hurricane Sandy. He made heat maps of collision hotspots (with one in 3-D) and included photos of the problematic intersections.

The engineer then turned to the data, looking at all bikes involved in collisions between August 2011 and September 2013. He also compared the number of crashes inside the Citibike zone, outside the Citibike zone, and overall.

While Swanson’s graphs show that the number of crashes within the Citibike area increased after the pilot program launched in May, they also show that overall collisions increased, too–and relative to the overall count, crashes within the Citibike zone adhere to historical ratios. The areas prone to the most collisions, meanwhile, come as no surprise: Intersections off the West Side highway, the narrow roads in the financial district, and the mouth of the Williamsburg bridge.


“Basically what I found was nothing, in a sense. There was no discernible impact one way or another,” Swanson said. “All those extra bikes out on the street–what is it, 10 million miles, and 5 million rides–we’re not really seeing any noticeable effect on bike collisions in the city. If you look at injuries to cyclists, it’s the same.”

As for what could be causing marginally higher collision numbers overall, Swanson points to mildly increasing congestion. Another factor, however, could be New York City’s speeding epidemic. In 2012, the number of people killed in speeding-related crashes increased by 65%.

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“I’m not the expert. I’m just the mapper guy analyzing it,” Swanson said. “Safety’s a factor that needs to be addressed overall in the city, I think.”

About the author

Sydney Brownstone is a Seattle-based former staff writer at Co.Exist. She lives in a Brooklyn apartment with windows that don’t quite open, and covers environment, health, and data.

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