St Pancras used to have taxi access to the old platforms 5 & 6 for arrivaing trains, but that stopped some considerable time ago. (By the time they filmed the opening shots for 'Porridge' where the prison van comes into the station.) The rank near the ticket office was rather more the area for those coming to the station.
Euston opened a cab rank road between platforms 1 and 2 in 1873, accessed from what is now Eversholt Street, but I am uncertain when it went.
Liverpool Street used to have a cab road between platforms 10 and 11.
London Bridge terminus between Platforms 16/17 and 18.
Cannon Street between Platforms 3 and 5, and after 1926 platforms 5 and 6, but it had gone before 1966.
Waterloo's cab road was between 11 & 12.
Charing Cross had a very short cab road between platforms 5 & 6.
Victoria, effectively two stations in one, had a cab road in each half until at least 1960.
Paddington actually had two cab roads, one between platforms 8 and 9, the other between 10 and 11.
Marylebone's cab road was between platforms 1 & 2 (which were on the East side of the station.)
Most of these cab roads were originally on platforms designated as the 'Arrival' platforms for the particular station. But as trains became multiple units or 'push-pull' the distinction between arrival and departure platforms was lost, and it seems that is when the cab roads went out of use.