Introduction

How do we measure whether a bike boom is, or is not, happening? By mileage cycled, or bicycles sold? There are good stats for the latter, fewer and often less reliable ones for the former. Or how about modal-share, the percentage split between different modes of transport? Some cities have certainly seen expanded cycle usage—for instance, between 2000 and 2015 New York City witnessed a 381 percent growth in its bikeway network and a 207 percent rise in bicycle trips—but dig down and the impressive jumps often turn out to be starting from pitifully low bases. Going from, say, 1 percent of all journeys to 2 percent is, indeed, a doubling in cycling use, but in big-picture terms it’s more of a blip than a boom. And not all of the increases in cycling trips can be put down to the provision of bikeways. Seattle has seen a 235 percent growth in its bikeway network over the last fifteen years and a 123 percent uptick in bicycle trips, whereas Portland, Oregon, saw a 391 percent growth in bicycle trips in the same period, even though its bikeway network grew by “just” 53 percent.