The evidence is piling up that the absolute best way to improve bicycle safety is by increasing the number of riders. It’s not helmets, it’s not bike lights. In fact, the new riders don’t even need to be experienced riders. There just needs to be more of them.
Elly Blue wrote an excellent column for Grist laying out the argument. Bike lanes, cycle tracks and other infrastructure clearly prompts more people to take up the bicycle. Cities with more bike infrastructure typically have better safety records. But perhaps it is not the lanes that make bike riding safer, but the fact that they urged more people to ride:
Research has been steadily showing, actually, that the more people are out there riding bicycles, the safer bicycling becomes. As ridership goes up, crash rates stay flat. It’s happening in Portland (see page 11 of this report [PDF]). It’s happening in New York City.
Public health researcher Peter Jacobsen carried out a fascinating study in 2003 about the safety in numbers phenomenon. The correlation between the number of riders and rider safety is clear, according to the report:
The Growth Rule implies that, over a wide range of circumstances, if cycling doubles, the risk per cyclist will fall by about 34%. Conversely, if cycling halves, the risk per cyclist is likely to increase by a staggering 52%.
Much of the safety increases may be attributable to changes in driver behavior. The more bikes, the more used to them drivers become. And this makes sense to me, because Seattle drivers are incredible compared to other cities I have lived in. Almost all of them are courteous, give me the space I need to feel safe, yield to me when I am huffing my way up a hill, and wait behind me if there is not sufficient room to pass. Clearly there are exceptions out there, but this is most certainly the norm, and I love it. Compared to drivers in Kansas City, Seattle is practically Amsterdam (though I hear things in KC have gotten better).
But imagine if the number of people riding bikes doubled. According to this study, the risk to each of us would go down 34 percent. Safety is by far the biggest concern among potential bike riders. Lucky for us, the more people riding bikes, the safer it gets, the more people ride bikes, etc… What a wonderful feedback loop of safety and bicycles!