As a former TOC Controller I can't recall being it being stated that Control should authorise the opening of doors in these circumstances.
When I have been asked, the majority of times my response was along the lines of - so long as it is safe to do, reach a clear understanding with the driver/other crew and advise any passengers not to venture too far as the train could go at any time. (There may have been a very small number of occasions when circumstances were such that opening the doors was not suitable).
When I have been asked, the majority of times my response was along the lines of - so long as it is safe to do, reach a clear understanding with the driver/other crew and advise any passengers not to venture too far as the train could go at any time. (There may have been a very small number of occasions when circumstances were such that opening the doors was not suitable).