Terrafugia is looking to create a car/plane hybrid. They expect it to be on the market by 2010, possibly earlier. Fantastic concept! Being able to leave the road and make it to a distant city in about half the time required by car would be great, not to mention just being able to drive away from the airport.
Fantastic mileage: 30 miles a gallon in the air, 40 on the highway. But this right here is the obvious downfall. You might not know how light a small 2 seater aircraft is but mileage like that should give you a clue. I do not have specifications on this new design but it IS smaller than the ubiquitous Cessna 172 which is a 4-seater so it is likely heavier than the hybrid will be.
The Cessna 172S weighs 1,663lbs when empty. The low end Chevy Aveo weighs 2,343+ empty with the Chevy Suburban weighing as much as 6,074 empty. Now in the case of a car that weight is centered almost entirely around the passengers and therefore all that weight helps to protect them in a crash with another vehicle. Planes are very different. A not insignifigant amount of weight is in flight surfaces which spread out away from the passengers and conveys no benefit in an accident. Some of this is mitigated by the flight surfaces being tucked right next to the hybrid while in car mode but there will still be the signifigant issue of being much lighter than the other vehicles on the road.
There is no question in my mind that this hybrid will fly and be safe in the air (pilot dependent of course) but it will be extremely dangerous to its passengers while on the road. That being said I like it, and as long as the dangers are known than I say bravo to anyone who decides to leave traffic behind.