Ever wondered why only the Jubilee line has the sliding doors on the platform that stop you getting blasted by wind Marilyn Monroe-style whenever the trains come in?
Well, one of the main reasons is that they're awkward and pricey to retrofit to existing platforms. Nonetheless, TfL has confirmed that the Piccadilly Line will be getting Platform Screen Doors (or Platform Edge Doors), as they're properly called. But not for ages.
The doors obviously have to sync up perfectly with the doors on the trains, which will require all the trains on the line to be the same. And the fancy new Siemens trains aren't arriving until 2024, so it'll be a while before all the existing ones are swapped out.
TfL has also told Londonist that "all deep line tube stations are under review for retro-fits," so we might start seeing them everywhere. Still, it's likely there'll be some stations where it just can't be done, like on the current Jubilee line where the doors are only at some stations.
The platform screen doors serve lots of important purposes: they stop suicides, they don't let people shove others in front of trains, they don't allow rubbish to get on the track, and they control the wind down in the tunnels.
What do you think – good news or unnecessary nanny-stating in a capital that's used to minding the gap? Let us know in the comments.