Throughout the Northwest, transportation planners predict traffic volumes will grow and grow. And they think we need to build massive, multi-billion dollar road projects—including Portland’s Columbia River Crossing, Vancouver’s Gateway Program, and Seattle’s deep-bore tunnel and 520 bridge—to deal with the inexorably rising tide of traffic.

But over the past decade, actual traffic trends have bucked predictions. In some places, traffic volumes have held steady; in others, they’re falling. This conundrum got Sightline researcher Clark Williams-Derry asking, “Dude, where are my cars?”