Every chance I get, I give the Seattle Times the unsolicited advice–free!–that every news story they do should have some kind of visual representation of data to go along with it, or, even better, form the foundation of the story. There’s nothing like a strong visual to make you confront subconscious assumptions. So I’m a big fan of their infographic department, and here’s the latest example.
Using data from Seattle’s department of transportation, the Times‘ Justin Mayo has created a Tableau map of more than 1, 800 collisions involving a bicycle from 2007 to 2011. My own infographic skills are not up to dropping an overlay of Seattle’s bike lanes on this map, but glance back and forth and tell me if you see what I think I see.
On the one hand it’s not surprising: The majority of collisions occur where cyclists and cars are trying to share busy streets: Dexter, 12 Avenue, Pine, Broadway. Because of Seattle’s geography, bicyclists often arrive at the same choke points as cars, and everyone tries to funnel through. But also, cyclists gravitate towards the bike lanes and sharrows that the city has laid out for them.
You wouldn’t want to assume that bike lanes on busy streets and arterials are more or less dangerous than residential streets without being able to compare proportional bike traffic, and I don’t believe we have data that granular. But what you can say is that bike lanes clearly grant no immunity from collisions. And if they aren’t the safest option (pros and cons), is that really a road we want to paint ourselves into?
“Over the past three years, SDOT has installed 40 percent of the bike lanes and sharrows described in the [Seattle Bicycle Master Plan],” says the department of its handiwork. I would be concerned, looking at the map of collisions over the same period, that the concentration of incidents on those very routes is arguing against the success of the enterprise. Somewhere between the multi-use splendor of the Burke-Gilman Trail and paint must lie a happier, safer medium.
