In the last few days Cockfosters has become the 80th step-free tube station. The number passed 70 as recently as 2016, and works are currently in progress to bring the total up to 97.
The new step-free station has yet to appear on the digital map available on the TfL website, but was added prematurely to the paper tube map released in May. A white wheelchair blob now exists at the northern end of the Piccadilly line, which is all very well and good but also means the terminus 'bar' has been lost.
Harry Beck introduced this iconic design feature back in 1933, with Cockfosters one of the ten terminus stations so marked. But with the advance of step-free stations, Cockfosters now included, only one such terminus bar remains. Perhaps you can work out where it is before I complete my exposition a few screens down.
Two things have brought the terminus bar to the edge of extinction - the accessibility blob and the interchange circle. Their joint assault began almost 20 years ago.
At the end of 2000 the tube map included 25 terminus bars...
2000: Amersham, Brixton, Chesham, Cockfosters, Edgware, Epping, Harrow & Wealdstone, High Barnet, Kensington Olympia, Mill Hill East, Morden, Richmond, Stanmore, Upminster, Uxbridge, Walthamstow Central, Watford, West Ruislip, Wimbledon; New Cross, New Cross Gate, Shoreditch; North Woolwich; Beckton, Lewisham
...but in May 2001 eleven disappeared...
Lost 2001: Amersham, Brixton, Harrow & Wealdstone, Richmond, Upminster, Walthamstow Central, West Ruislip, Wimbledon; New Cross, New Cross Gate; Lewisham
...transformed into interchange circles because they were also National Rail stations. Kensington Olympia was circled the following year, as it probably originally should have been. The total was now down to 14.
Lost 2002: Kensington Olympia
Step-free blue blobs first appeared in 2006. There weren't very many back then, but several terminus stations were already accessible because steps aren't always required at the end of a line. North Woolwich also disappeared that year when the station permanently closed.
Lost 2006: Chesham, Epping, Morden, Stanmore, Uxbridge; Beckton; North Woolwich
There were now just six terminus bars left. Two more disappeared in when 2009 step-free access came to the northern end of the Northern line.
Lost 2009: Edgware, High Barnet
Shoreditch had closed by this point and lingered on the tube map only as a replacement bus service. It vanished after the East London Line joined the Overground in 2010.
Lost 2010: Shoreditch
A decade-long pause in terminus bar abolition followed. It was broken earlier this year when Mill Hill East finally got its lift. Cockfosters now joins it, bringing the total down to just one.
Lost 2020: Cockfosters, Mill Hill East
The only remaining terminus bar, if you haven't worked it out by now, is at Watford. By rights it should have disappeared a few years ago when the Metropolitan line extension opened but, with that project cancelled, Watford's unique situation should continue. Along with a half-bar at Aldgate it is the sole survivor of Harry Beck's intended end-of-line design.
Nothing says 'tube map' quite like a terminus bar. They have alas all gone, bar one.