This illustration shows how City Cars stack together.
Credit: Franco Vairani
The wheels also enable incredible maneuverability. Instead of making U-turns, the car can spin on the spot, and when the driver turns each wheel 90 degrees, the car can parallel-park by moving sideways.
"The idea for a wheel motor has been around for a long time," says Peter Schmitt, designer of the wheel. But Schmitt says that the advantage of his design is that the wheel is controlled by software instead of by mechanical coupling.
The MIT team's vision of deploying these cars in a shared-use, personal-mobility system isn't new either. In Lyon, France, a company called Velo'v recently introduced a shared-use bicycle system throughout the city. Based on its initial success, the Velo'v system is being extended to Paris with approximately 2,000 stacks and 20,000 bicycles.