Seattle spent roughly $99 million on bicycle infrastructure over a decade, adding more than 76 miles of bike lanes and greenways. Yet between 2014 and 2023, while the city’s population grew about 13 percent, the number of people commuting by bicycle fell from roughly 14,157 to 12,600. Bike commuting’s share of commuters dropped from 3.7 percent to 2.7 percent. Portland saw an even steeper decline. It’s a striking reminder that infrastructure spending is an input. What matters is whether people actually change their behavior as intended.