Dwight's blog, It's Time to Reinvent Transportation

It’s Time to Reinvent Transportation

Seems to me it would be possible to do public transport that is more flexible that what we have today. Imagine:

pod-sized transports that run on rails
computer controlled
automatic track switching
powered electrically by the tracks

What was a train then becomes more like a car — with some of the advantages of both.

There is an analogy with packet switching in computer networks. Think of each pod as a packet. We can get anywhere (that tracks exist) without interfering with others. A station might look like this:

Pods that are not stopping go by without slowing down. Pods that arrive at that station switch to the loading and departure bay. If passengers are waiting to depart, computer systems send empty cars to the station.

With switching, there is no need to have different “lines” : instead we just get in, tell the car where we are going, and get switched appropriately along the way. Things could then get very granular, for example with end points in large buildings.

A few other notes:

you never do a train to train “transfer”, as one would in a conventional system. Imagine going from nearest station directly to the specific airport terminal of your flight
could replace an existing network of both buses and trains
wait times at stations for the “train” to arrive should be much lower, often zero
if there is a problem somewhere, the computers automatically reroute pods around the problem — much like in a network
if a car has failed but can still roll, the car behind it could push it to the nearest maintenance station
if many cars are heading along the same route, they can run close together and “draft” getting some of the same aerodynamic efficiencies of a long train
unlike a long train, it’s easy to change elevation with such a short vehicle. Ground-level loading stations, which then submerge, wouldn’t be too hard. Likewise we could ahve a second floor station in a large building, out of the way of the pedestrian entrance.

The key is a computer system coordinating everything. The system would know where each pod is at all times. Unlike a computer network, we can’t drop any packets. :-) This is doable. There are ways to engineer fail-safes, such as plain old crumple-zone style bumpers, in case a series of hardware faults and/or bugs did run two cars into each other.