Monday, December 09, 2013

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.

6 comments:

Chrissy said...

I'd put your "don't call it an accident map" warning higher up. :)

1138311 said...

Huh. That's interesting - I got hit by a car in spring of 2012 at the intersection of 7th and Spring Garden, but it doesn't show an incident there. Called the cops, filed a report on site with witnesses and everything. Are the cops underreporting?

Nicholas Mirra said...

If you weren't hurt and there was no damage, it might have been recorded (for PennDOT's purposes) as an unreported crash.

The other possibility is that, unfortunately, the Philly Police are known to sometimes categorize bike-car crashes as pedestrian-car crashes in their reports. This is due to some combination of bad paperwork, ignorance, or laziness.

andrewlevitt said...

Ditto on the unmapped, police-reported bike crash from fall 2012 on 13th St. Bike was destroyed.

Corey said...

i see no problem using the term "accident"; sure there is usually someone or something to blame in a crash, but rarely is a crash intentional; hence the term "accident".

1138311 said...

In my case, bike was unrideable afterwards (wheel taco'd, fork bent)and I had to go to the ER to get my neck checked out and the huge gash on my left elbow treated - there was so much bleeding that the witness to the crash gave me a t-shirt out of the trunk to keep blood from getting everywhere. I would think that meets the qualifications of injury and damage.