This Map of Philly Reveals the Locations with the Most Bike Crashes

This summer we had the pleasure of being part of Azavea's Summer of Maps program. We worked with grad student Tyler Dahlberg on several mapping projects related to bicycle activity in Philadelphia. One of the products of that collaboration we are excited to share here.

This map shows the locations of reported bike crashes in Philadelphia between 2007 and 2012. You can also view the map here.

The red dots on the map don't get more red with an increase beyond 4 crashes ("It's like, how much more red could this be? And the answer is...none, none more red.") Drilling down into the data reveals the locations with the greatest number of reported bike crashes:

1. Broad & Spruce - 10 crashes
2. Broad & Pine - 9 crashes
3. Broad & Spring Garden - 9 crashes
4. 34th & Spruce - 8 crashes
5. Broad & Washington - 7 crashes
6. Broad & Vine - 7 crashes
7. Schuylkill Ave & Chestnut - 6 crashes
8. 38th & Spruce - 6 crashes
9. 38th & Market - 6 crashes
10. 16th & Arch/BFP area - 5 crashes
11. 30th & Chestnut - 5 crashes
12. Broad & Walnut - 5 crashes
13. 5th & Market - 5 crashes
14. 22nd & Market - 5 crashes

There are some important caveats to be considered when looking at this map:

• This does not take into account bicycle volume. Broad & Spruce also sees some of the highest rates of bicycle traffic in the city, making the rate of crashes there significantly lower than this map would suggest.
• These are only reported bike crashes. Many bicyclists do not report their crashes to the police, either because there was neither injury nor damage, or because they believe (falsely) such things should not be reported to the police.

We will be doing further analysis to combine this data with bicycle volume data to determine which intersections see the highest rate of crashes and why that might be so. But one place where this map dovetails with intuitive feelings and conventional wisdom: Broad Street is not a good place to ride a bike. Hey Philly bicyclists: take 13th or 15th Streets instead.

And lastly, if you're a writer covering this map for another outlet, we don't want to see you call this an "accident map." These are crashes, not accidents. Most bike crashes are somebody's fault, be it the bicyclist, the driver, the pedestrian, or the built environment. And crashes can be prevented.

Like this work? Want to see more of it? Do your part by becoming a member of the Bicycle Coalition. Membership is what allows us to keep working for the safety of bicyclists in Philly and beyond.

Estimating a Bike Theft Neighborhood Index for Philly

[Ed. note: the following is a guest blog post from Ken Steif, a Doctoral Fellow in the City & Regional Planning Department at the University of Pennsylvania]

In anticipation of this weekend's Apps for Philly 'Hackathon' which is focused on transit and transportation, I did some tinkering with a bit of data on bike thefts throughout the City.

We know that there are a variety of locational factors that influence a thief's decision to steal a bike. Many of these probably have something to do with the built environment, like lighting or proximity to a bar or restaurant where a patron might witness the crime. There is also likely a temporal component involved as well - perhaps more bikes are stolen in the warmer months.

Given these patterns, I thought it might be possible to capture some interesting dynamics by estimating a Bike Theft Neighborhood Index. The index effectively plots thefts over a time/space continuum, illustrating how the monthly pattern of incidents vary across neighborhoods.

Click for bigger version

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We (the Bicycle Coalition) collaborated with local map and data whizzes Azavea this year on bike theft as part of Azavea's Summer of Maps program. We will have a more detailed report on the results of that collaboration later this fall. In the meantime, remember to deter theft by securing both wheels and your frame to a pole or rack that cannot itself be cut or pulled from the ground.