PAL-V Europe NV started in 2001 to design a roadable aircraft. What they came up with is very interesting indeed. It’s a two-place (two seater) gyroplane which behaves like a souped-up 3 wheel motorcycle on the road (yes, it leans!)
There are always compromises when trying to come up with a machine that works both in the air and on the road. Historically, companies working in this area emphasize the air, and give you a “roadable” machine which has pretty lousy performance, but gets you from your garage to the airport, and that’s about it. PAL-V, on the other hand has really worked on the road part of the equation, producing a vehicle which delivers high performance (112mph), has good range, and seems like it would actually be fun to drive.
As far as the airborne side goes, an gyroplane is an interesting approach. It is a rotary wing craft, but the wing is not powered, it rotates from forward air pressure. This means you can’t land or take off vertically, but it is a lot simpler and cheaper than a helicopter’s rotor mechanism. It is quieter than a helicopter as the blades spin much slower, it takes off and lands at low speeds, and can’t stall. In the event of an engine failure, it can be auto-rotated to a safe landing. It’s designed to fly below 4,000 feet in uncontrolled VFR (visual flight rules) traffic. They say it will do 112mph in the air as well as on land!