Fred and Barney used their legs to propel their primitive vehicles. You and I might start using our arms. Thinking about how sweaty we're all going to be once we get to work makes me wish these designers watched more of The Jetsons.
Luckily, we'll get some assistance this time. The HumanCar Imagine integrates the company's powered-by-people technology and combines that with a stylish hull and an electric motor. The rowing motion of the passengers propels the buggy and to turn they (hopefully) all lean in the same direction. The electric motor should keep the ride from getting uncomfortable while still providing passengers a bit of a workout. You might not pass the Imagine on the highway, but maybe it'll replace multi-seater bikes and short range transport like golf carts. The Imagine is still just a concept.