Christmas comes but once a year – but new tube maps pop up about once a fortnight. And that, my friend, is why Sadiq Khan is better than Santa.

Today’s map isn’t technically a tube map at all: rather, it shows what Transport for London’s suburban rail network would look like, if it gets its way.

TfL has its eye on services currently run by operators including South West Trains, Southeastern and (spit) Southern. Its plans would mean swallowing suburban services that run into Moorgate, Waterloo, Victoria, Cannon Street and London Bridge.

The new map also shows Crossrail, and the proposed Overground extension to Barking Riverside. Here’s the map:

Click to expand. If you want to see a really big version, expand it, right click and open the image in a new tab.

That’s a large chunk of London’s rail services. So it probably makes most sense to lay out what it doesn’t include:

  • The Lea Valley line, from Liverpool Street or Stratford via Tottenham Hale;
  • The Chiltern lines into Marylebone, and C2C lines into Fenchurch Street;
  • The faster Southern trains through East Croydon to suburban destinations in Surrey like Tattenham Corner and Caterham;
  • Services on Thameslink, both north towards Luton or (in future) Finsbury Park and beyond, or south towards Sevenoaks and the Wimbledon/Sutton loop. (Though the loop itself, oddly, is shown.)

It’s the last of these that is the oddest exclusion. Thameslink is a sort of Crossrail v0.5 – a heavy rail line that can double as part of the central London transport network.

But the reason for its exclusion from the map presumably reflects the limit of TfL’s ambitions. TfL wants to run all suburban services, but has no interest in running longer-distance ones. On Thameslink, you can’t really separate the two. 

In the same way, while C2C or Chiltern do stop at suburban stations, those services are primarily there to serve stations outside London’s borders. Sadiq Khan has no plans to extend his empire to Aylesbury or Southend.

TfL is considering Khan’s proposals. This map – and the excitement it generates among grumpy commuters – is presumably meant to generate some helpful public pressure before the government considers the full business plan later this month.

Jonn Elledge is the editor of CityMetric. He is on Twitter, far too much, as @jonnelledge.

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