One fundamental issue to be addressed is the rules under which fully automatic trains will operate as it will probably make no sense to try to mimic what we have today with crew operation. Are signals needed by the trackside.
Are signals by the trackside in all cases (in cab signalling for example)?
There is then the question of whether we want to do it or do we prefer to keep drivers jobs.
Deltic said:
"This is not a discussion about the rights and wrongs of driverless trains but the technology which they require"
To answer his specific question - I believe the technology exists (or is under active field testing), however there's little financial incentive at the moment, and there's little movement by the rail companies as a large conservative oil tanker of an industry. However technology constantly gets better and cheaper, and the same applies to automation - it's inevitable -- even if the railway doesn't adapt, successful fleets of automated taxis that are cheaper per mile than a train will cause many branch lines to wither. A taxi to Crewe from my house is £15. The train is £1.50 each way, but with a network of automated cars it could also be £1.50, or even less. At that price, why would I bother with the train, even if it were free?
I don't see long distance high speed trains vanishing any time soon, but the Abbey line being paved over as a peak-flow automation-only car lane is something I could see happening in 20-30 years.
To answer the rights and wrongs, that's a far larger societal question, drivers are not a special category of person, people have lost jobs to automation through the ages, it's inevitable, be they secretarial pools, travel agents, claim adjusters. Even when there's no direct job losses, you find that automation allows a company to do more with the same number of people, where before they'd have to employ more. In days of yore there's be 2 or 3 people driving a train and half a dozen people on each station. That doesn't happen now.
How we deal with that as a society is something that could range from a post-apocolypic hellhole to a utopian society. It makes no sense to me to have people spending time jobs that could be automated, far better to increase the time people have to perform leisure. Currently the UK has a population of 65 million, of which 30 million work say 40 hours a week, so 1.2 billion hours a week. If we can automate society so 10 million of those people don't need to work, but there's 2 million new jobs looking after the new technology, that is the same output with 22 million working 40 hours a week, so 880 million hours a week. That means we have 320 million more leisure hours as a society. That's a good thing.
The trick is to ensure that work
1) gets done
2) is equitably shared
(1) is usually by reward for many of these automatable jobs. Who would do their job if they got paid regardless?
(2) is a "fairness" thing. Why should I get up at 6AM to go to work when my neighbour doesn't have to. Reward feeds into this too.
Finally there is the question of where to start? In my opinion certainly not on one of our major trunk routes but more likely on a self-contained sub-network.
We've already started. Heathrow T5 for example is an automated train that doesn't have a drive. Neil already suggested Stourbridge.