Even assuming that a personal craft could be built economically, how
would it improve anything? Just picture the normal traffic on a
freeway translated into the air. Hurts to even think about it.

Hand in hand with the developments in smaller "personal" air vehicles
is the development of computer controlled (and extremely automated)
flight control systems that won't just control the individual
aircraft, but act as a management system for ALL of these aircraft in
a given area. People won't fly these things (unless they head out
into the boonies); they'll simply be passengers.

You may have seen examples on TV of the automation systems being
developed to control vehicles on the highway. These systems use a
bunch of different technologies (radar, magnetic sensors, "signposts"
embedded in the roadway, etc.) to take over the driving responsibility
and allow the computer to guide the vehicle at high speed within
inches of the other vehicles on the roadway.

As I understand it, NASA's plan is to extend this type of thing by a
couple of orders of magnitude - into three dimensions (up & down in
addition to left & right and front & back) and with some sort of
artificial intelligence system to guide all the individual planes.
The plane would probably be responsible for keeping itself airborn and
moving at the right speed and in the right direction, but the AI
management system would be telling all the planes where and when to
go. After getting in and telling the computer the destination, the
craft's occupants would simply be along for the ride.

Part of me thinks this is a developing technology looking for a
problem to solve, and part of me thinks it could be a wonderful cure
for traffic congestion in the urban sprawls. Either way, it is so far
away from what this newsgroup is about we might as well be discussing
submarines.

If it they actually make it work and the whole thing takes off, a lot
of people will get a good idea of what the early astronauts meant by
"spam in the can."

IMHO, anyway.

Rob