Suburban Ride-Sharing Is Mathematically Impossible

Given the proliferation of microtransit services trying to match drivers and passengers, you might think they had ride-sharing and carpooling all figured out. But the recent demise of Leap Transit in San Francisco—to say nothing of the other transportation start-ups that have failed without a media whimper—reminds us that even in a big city it’s not easy to fill empty vehicle seats. And in the suburbs, it’s downright mathematically impossible.

Or just about, anyway, according to a provocative new thought-experiment by Steve Raney, principal at a smart mobility consultancy called Cities21. In a working paper, the former Silicon Valley tech product manager crunched the numbers on ride-sharing in the Palo Alto area and found the odds of matching drivers with passengers long, to say the least. Raney calls it the “Suburban Ridematch Needle in the Haystack Problem.”