Keith Bibby wrote:all the trains need a guard
And all cars need a man walking in front of them with a flag!
London Underground Tube trains haven't had guards since 2000.
Having said the above I feel there is a need for train crew (in addition to the driver) on many services and performing different tasks, depending on the train service being provided and the route it is on.
But the issue is too complex to tie down to one simple solution of a guard.