My local line past the house for many years. "Driven" from the front for several reasons, which can include being fully automatic driving but them just doing the doors from there, which is why there are mirrors/CCTV at all stations. If really being driven manually there is now a speed limit and the 4-way flashers on the car ends, like a tram, are flashing. Other reasons are if there are workers on the line (to sound the horn), reports of trespassers, or on empty trains non-stopping stations, again to sound the horn at each one. This likely accounts for trains reversing at Canning Town, not a scheduled service point but now going empty to the depot at Gallions Reach. They all used to run in service to and from here but the latest concessionaire stopped this.
There were two separate sidelong collisions a good while ago southbound at West India Quay with manually driven trains colliding, one of which I actually witnessed from the road below, although I didn't know so until I saw the evening news.
And a further reason, especially in winter, is, as one of them told me one day, "it's warmer up here than at the doors". This used to be pretty optional, but the accident at Bank where a passenger was trapped and dragged, just managing to escape from their caught coat in time, led to a substantial restriction on this. There were various comments by me on here (use the Search) at the time of the RAIB report into this into how managed, or not, such operation from the front had become.
I see the new trains on order have a more substantial division for any staff working from there, although it doesn't happen that much, done by reducing the forward-facing seats, always the most popular on the train especially for tourists, at all times. Good old operations triumphing over customer convenience.
Old fashioned or not, I still call the staff the Train Captain. Can make them smile!