“MARK my word,” Henry Ford declared in 1940, “A combination of airplane and motorcar is coming. You may smile, but it will come.” No doubt flying cars will eventually make their fashionably late arrival on the scene. But for the more immediate future of transportation, best is to take a look at a less futuristic and, ahem, more down-to-earth trend: carpooling. This month Uber, Lyft, and Sidecar all launched carpooling services in San Francisco. Users can opt to share a ride with a stranger travelling along the same route at the same time for about half the price of a solo journey. Uber is in raptures at the disruptive ingenuity of its new service called UberPool: “The implications are profound… This is a bold social experiment… a brave new world.”

Yet a more interesting variation of the concept (which has been around for quite some time on the old continent in the form of sites such as BlaBlaCar and Mitfahrzentrale.de) is the service offered by Bridj, a startup based in Boston. It crunches data from many sources, including Google Earth, Facebook, the census and municipal records, to see where people live and work. The results are used to create routes that respond to commuters’ needs, rather than force them to conform to existing routes, many of which no longer match the flow of traffic. As more people use Bridj, plugging in their points of origin and destination, the “smarter” the system becomes, supplying customised, pop-up routes where people need them. The firm’s data scientists can even anticipate popular routes—for instance, in advance of a major concert or sporting event.

Average Americans in an average American city, explains Matthew George, founder of Bridj, currently have access to only 30% of jobs in their metropolitan area via 90 minutes of public transportation. The promise of Bridj, which works with local bus operators, is to save commuters time with more reliable service, no transfers and fewer stops than public buses or subway trains. A two-mile ride from Coolidge Corner to Kendall Square on Boston’s “T” train takes about an hour; Bridj’s direct shuttle (pictured) makes the same trip in 20 minutes. For many commuters, the convenience is worth the marginal price increase: at $6 per ride, Bridj is less than a taxi but more than a ride on Boston’s subway ($2.50) or the city bus ($1.50).

Creating better routes to high-density destinations doesn’t sound terribly revolutionary, and carpooling might not be the sexy mode of travel envisaged for the 21st century. But the economic and environmental consequences of this shift could be important. Carpooling services could disrupt public-transport systems in much the same way that Uber and Lyft are disrupting the taxi industry.

Bridj, for instance, promises to be economically inclusive, but it is more likely to service consultants and comfortable tech employees than Boston’s minimum-wage commuters. And by taking customers away from subways and buses, it threatens to drain public transit systems of much-needed funding, which could drive up costs for those who rely on public services. Getting some people to their jobs faster may come at the cost of depleting access for others. Every disruption has its losers and winners. That will certainly also be the case when flying cars finally land.