A quiet roundabout revolution is sweeping America’s suburbs. And it may have continued, unmeasured and unremarked, if not for Lee Rodegerdts.

It turns out the fine folks at the U.S. Bureau of Transportation Statistics don’t track the nation’s roundabouts, rotaries or traffic circles. Indeed, no federal agency does. Instead, that weighty responsibility has, for a quarter of a century, fallen on the unassuming shoulders of Rodegerdts, an engineer and talented amateur photographer and pianist in Portland, Ore.