[I am Richard Brandon]

Not quite good enough mon ami. Trains can run into each other when one is stopped - say, signal failure - and the computerized detection system is also not working. Maybe not so many are killed but when you are dead, you don't care if 'spread the death' is working or not.

[101voodoo]

Really, there is no comparison when contemplating the disaster possible with unmanned aircraft and unmanned trains.

An aircraft which loses power and has no pilot on board will fall to earth, crash and likely kill all a board AND if over a major city possibly hundreds if not 1000’s more.

If a train loses power and is dead on the tracks at least a signal can be sent to other trains on the track to stop. There are all manor of battery back ups which would allow communication with the disabled train and at the very least get the people out of it. These same systems (communications) can be used on an airplane to be sure. But where will the passengers go? Stepping down from a train is a bit easier then stepping down from an aircraft spiraling down from 35,000 feet.

Case closed