They're called bicycles, motorcycles, buses, and trains. The first two give up protection from the elements, the second two give up independence. Keeping both the constraints nets you a single-person car-like device with say a 30hp motor - somewhat more efficient, but not enough to drive adoption. Gasoline (and energy in general) just isn't expensive enough for any of the alternatives to be taken seriously (infrastructure-wise) anywhere but dense urban areas.