I recently commented on Dave Schlabowske's blog entry about the recent deaths of two cyclists in Dane County. I'm reposting the comment here, because I've been thinking about how we use statistics in our bike advocacy for a while now.
Here's Dave's post: http://bfw.org/2012/10/09/two-killed-in-dane-county-in-six-days/ and my comment: ~~~~~~~~~~~~~~~ As much as I'd like to convince more people that biking is safe (and fun!) (and healthy!) (and good for the planet!) I take issue with the statistics that bike advocates repeatedly use to demonstrate that biking is as safe as driving a car. There are some serious problems with the statistics themselves, and with how we approach what safety means to most people. Consequently, I think we're unlikely to persuade anyone with aggregate statistics that lump everyone who drives or bikes together. I have no doubt that I am less likely to be killed riding my bike to the coop on a cozy Madison bike path than driving my car to Spring Green on a curving, undivided highway, but that doesn't mean that it would be safer for me to ride my bike to Spring Green than to drive. Nor does it mean that it's safer for me to ride my bike to the coop than to drive. I don't flip a coin when I decide to bike or drive. The shorter, sunnier, and safer the trip, the more likely I am to ride my bike. The longer, darker and more dangerous the trip, the more likely I am to drive or find some other transportation. I suspect I'm fairly typical in this regard. Unless there are a lot of coin flippers out there, or a lot of people who look out the window in January and say "The roads is really icy and there's a blizzard predicted for this afternoon. I'll ride my bike instead of driving. It's safer!" aggregate statistics like the ones cited above do NOT show that biking is safer than driving. Another reason that these statistical arguments fail to convince non-riders is that they rely on a narrow idea of what it means to be "as safe as." People are far more likely to judge safety by comparing outcomes in similar situations, rather than by looking at aggregate data for fatalities. This point follows on Pat's comment above about getting broadsided in a van. For just about any type of crash, you are much likely to be injured if you're on a bike than in a car. To most people, that means riding a bike is more dangerous than being in a car. Also, people care about all kinds of injuries, not just fatalities. A fender-bender in a car may cost a lot to repair, but the corresponding incident on a bike is going to be a knee-scraper or a bruise-maker or possibly even a bone-breaker. For a wide range of non-fatal crashes being enclosed in a ton of steel does make it less likely that you will be injured, in other words, it makes cars safer than bikes. I share everyone's sadness and distress when a car strikes down another bicyclist. I get extremely frustrated with sensational coverage of bike crashes and agree that it can cause people to overestimate the dangers of biking. But I don't think that relying on statistical arguments is likely to help us much. I applaud the diverse efforts that the BFW is making to promote safer biking and safer roads for everyone, and hope that this is the last time that a blog post like this is necessary. ~~~~~~~~~~~~~~~~~ Ann Ann Maria Bell Arboretum Cohousing
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