When I was in high school, I did a project on PRT -- Personal Rapid Transit. It was the "next big thing" in transit and of course, 30 years later it's still not here, in spite of efforts by various companies like Taxi 2000 to bring it about.

With PRT, you have small, lightweight cars that run on a network of tracks or monorail, typically elevated. "Stations" are all spurs off the line, so all trips are non-stop. You go to a station, often right in your building, and a private mini-car is waiting. You give it your destination and it zooms into the computer regulated network to take you there non-stop.

The wins from this are tremendous. Because the cars are small and light, the track is vastly cheaper to build, and can often be placed with just thin poles holding it above the street. It can go through buildings, or of course go underground or at-grade. (In theory it seems to me smart at-grade (ground-level) crossings would be possible though most people don't plan for this at present.)

The other big win is the speed. Almost no waiting for a car except at peak times, and the nonstop trips would be much faster than other transit or private cars on the congested, traffic-signal regulated roads.

Update: I have since concluded that self-driving vehicles are getting closer, and because they require no new track infrastructure and instead use regular roads, they will happen instead of PRT.

Yet there's no serious push for such systems...

Read on.

I've written before about automatic self-driving cars, both their risks (overregulation due to fear of their use by terrorists) and possible driving forces (oil companies excited by people taking longer trips) and more.

Generally, except for a few specialized applications (such as the automatic parking lot) such cars, if they are to be used where people or cars that may not under network control are present, must start with a basic ability to avoid accidents. In a vigourous debate with friend Charles Merriam last night, the question came up about where the value will lie. Charles is a big proponent of worrying first about crash-avoiding cars.

Right now we all pay from $250 to $500 per year, and often much more, for insurance to cover the risk of accidents. Of course, that's just the financial cost, and financial proxies for suffering, so the real value we would put on an accident resistent car might be much higher. Perhaps $5,000 to $10,000 over the life of the car.

That seems like a highly lucrative market on its own. While the self-driving car has many other long term merits (because you can do other work while moving, and you don't have to park it, and it can appear on demand as a taxi for you) we should be very close to financially justifying the accident-avoiding car today...

I hinted last week I would write about a peril from and to automatic cars, or actually any drive-by-wire cars.

That peril is they become highly useful terrorist weapons. Today terrorists get kamikazis to drive ordinary cars to attack targets and checkpoints. It will be easy to modify a drive-by-wire car (including the self-parking cars already on the market) to be controlled by the cheap remote controls found on toy cars and planes today, and easy to mount a wireless camera (X10, the terrorist's tool!) as well.

I seem to be thinking a lot about the future of automatic cars these days. Already we're seeing cars in Japan that can park themselves in a tight parallel parking spot, and this leads me to think that the next market for the technology, after the basic automatic highway, won't be the city street but the parking lot.

I'll be writing more in the future on ideas for auto-drive cars (both plus and minus) but let me start by asking the question of why the oil companies haven't jumped up to foot the bill for the development of automatic cars and highways?

It seems a big win for them. Given the availability of a car that would drive itself on the freeway and perhaps a few major roads, people would be much more willing to tolerate longer commutes, and that seems a win if you sell gasoline. A multi-billion dollar win.