Today's question is "Which tube line interchanges with the most Overground lines?"
And before we answer that the easy way, let's revisit one reason why Overground line names were so necessary.
This is part of the car line diagram displayed in Victoria line trains.
It shows that the Victoria line interchanges with the Overground on four occasions between Walthamstow Central and Highbury & Islington, but all four interchanges are identically labelled. It's a lot less useful than it could be, but this is because it's an old diagram and the lines hadn't been given names when it was printed.
TfL had hoped to have new car line diagrams ready to display on the tube last year when the new lines launched but funds were insufficient so they had to wait. In good news they may be months late but the new diagrams have started to appear, indeed on some lines the changeover is complete.
Here's the new car line diagram for the Victoria line, and as you can see it's much clearer.
At Walthamstow Central the interchange is with the Weaver line.
At Blackhorse Road the interchange is with the Suffragette line.
At Seven Sisters the interchange is with the Weaver line.
At Highbury and Islington the interchange is with the Mildmay and Windrush lines.
If I hadn't chopped the map there, you'd have seen an additional interchange at Euston with the Lioness line.
That's five Overground line interchanges altogether.
So can the Victoria line be beaten?
It would help if all the new car line diagrams were available to peruse, and the good news is they are. An FoI request last month revealed the lot, indeed several requests have, so you can now download all the diagrams for all the lines in a convenient zip file, simply by clicking here.
You'll see they're a lovely collection of pristine pdfs.
You'll see they're dated January 2025, but they've taken their time to be rolled out.
You'll see that the Zone strip along the bottom is now grey rather than blue, this because TfL have decided zones don't need to be quite so in-your-face as they used to be.
You'll also find that these haven't found their way onto all tube trains yet, indeed the Victoria line is well behind the curve.
Here's the inner London end of the Metropolitan line.
Three Overground lines get a mention, the Mildmay line, Lioness line and Weaver line.
Two of these aren't proper interchanges, they involve exiting the station and walking down the road.
The Mildmay line is a 450m walk from Finchley Road to Finchley Road & Frognal.
And the Lioness line is 340m walk from Euston Square to Euston.
I'm counting all of these as interchanges, so the Metropolitan line ends up with three.
You can do the same thing with all the tube lines.
And then you get this table.
And we discover this...
• Yes, the Victoria line interchanges with the most Overground lines, 5 of them
• Next come the District, Hammersmith & City and Northern lines with 4 each
• The Central, Jubilee and Metropolitan lines interchange with 3 Overground lines
• The Bakerloo, Circle and Piccadilly lines interchange with only 2 lines
• The Waterloo & City is the only tube line not to interchange with the Overground
• The Piccadilly line's only Overground interchanges involve a 600m walk at street level, none actually share the same station (they're Manor House ↔ Harringay Green Lanes and Caledonian Road ↔ Caledonian Road and Barnsbury).
• 10 Bakerloo line stations are also Overground stations (shadowing the Lioness line)
• 8 District line stations are also Overground stations (mostly on the Mildmay line)
• The Mildmay line interchanges with the most tube lines - 8 in total
• The Lioness line is second, interchanging with 7 tube lines
• The Liberty line only interchanges with 1 tube line (the District out at Upminster)
And if we overanalyse all this Overground interchange stuff we get...
» The Elizabeth line interchanges with every Overground line except the Lioness line (well done Liz)
» The DLR interchanges with only two Overground lines (at Shadwell and Stratford)
» You'd expect Thameslink to interchange with more than two Overground lines but it doesn't (only at West Hampstead and Norwood Junction)
» The trams only interchange with the Overground at West Croydon
» There are only two Overground/River interchanges (at Imperial Wharf and Barking Riverside)
» The cablecar is bloody useless
» There are only six places where the Superloop stops at an Overground station (Silver Street SL1, Walthamstow Central SL1/SL2, Barking SL2, West Croydon SL6/SL7, Shepherd's Bush SL8, Kenton SL10), this because the Superloop is generally further out than the Overground
» The Liberty line is the only Overground line not to interchange with the Superloop (it will next year)
tl:dr summary
• The Victoria line interchanges with the most Overground lines
• The Mildmay line is the interchangiest Overground line
