On 16/03/2017 16:23, Dave Plowman (News) wrote:

, could in the future a
collection of vehicles such as driverless cars virtually joined
together be classed as a train with vehicles dropping in and out as
required.

Ever been on a train where it drops off a few carriages? ;-)

For a while some trains to Cornwall from London had "slip coaches". The
back one or two would be decoupled while still running, with a spare
guard left with them to brake the coach to a stop at the station.

I think they could do this at a couple of stations.

(googling tells me other lines had them too)