Automobiles have played a huge part in American history, but the rise of the gasoline-powered horseless carriage was not preordained; they evolved in response to a specific set of circumstances. A century later, we may be at another turning point, ready for something safer, faster, less intrusive, and more economical. If we were to begin again, what would leading thinkers outside the auto industry, unburdened by tradition, come up with?

One way to reinvent the wheel is to replace it with legs. A two-legged car may sound far-out, but James Kuffner, head of the Planning and Autonomy Lab at the Robotics Institute of Carnegie Mellon University, has authored dozens of scientific papers that suggest such a scenario could be reality.

In theory, cars with legs could travel anywhere humans can walk, hike, or climb. Liberated from the wheel, autos would have no need for expensive, tar-covered roads, nor for many bridges or tunnels. Instead, dirt highways would teem with mechanical foot traffic leaping like fleas between concrete landing pads