Originally Posted by
layz
When I used to have to do that commute the train often made an unscheduled stop at Vauxhall which was useful for those who needed to connect to the Victoria line. This was only possible because of the slam doors, if the doors were driver operated then this wouldn't be possible.
That, of course, is one reason why slam-doors without locking are no longer used. Without driver or guard control, the train stopping for a signal means that there is a risk it may depart with people getting on/off unless you treat any stop in a platform as a station stop, which introduces delay.
Neil