A new line from North to South to ease capacity on existing lines? Sounds like a good idea, let’s build half of it.

I mean you have to sympathise with the souls of Kensington and Chelsea, imagine the horror of knowing that at anytime there might be a poor person only a few dozen metres under your house.

"I've been thinking alot about the London Underground....." is a statement that didn't really need saying :-)

9:41 "There is the West London Orbital, which I do not think I have yet covered on this channel."
Looking at the previous video on the channel

When they spilt the northern line the most northerly one should be called the southern line

There has always been plans to extend the Bakerloo Line,  when humans colonise Mars, plans to extend the Bakerloo line will still be proposed but not  constructed.

As a Parisian, most thought the metro network was pretty much done, with only a few extensions that needed building, merging 2 stub lines (3bis and 7bis). And then, out of left field, Grand Paris Express pops up as an actual project. With financing. Not just some crayons on a map (various plans existed for a long time, but everyone thought they were pipe dreams). And we get 4 new metro lines! With a more recent proposal for yet another line, M19!
So to Londoners: you never know!

Thank you JH, i think the 'tube' model is now sort of defunct for new London lines. The city is now so big that Elizabeth Line/Thameslink style is the way forward, reducing the inefficiency of trains sat in termini on the edge of town, and instead sending those under the centre. Have a lovely afternoon!

Obviously, if the Northern Line is split in two, whichever branch gets High Barnet should be named the "Beck Line", since the late great Harry Beck lived in Finchley. The man was treated terribly by TfL, he should have a permanent place of honour in the railway system!

I love Jago's speculative videos

I've liked the idea of naming the Bank branch as the Roman line, seeing as it goes through the Roman city and from Borough it follows a Roman road

It isn’t Sunday without Jago uploading a video at midday! He has arrived to end the final weekend of September on a good note. :)

There are absolutely tons of transport deserts in London, plenty of opportunities for new lines. The problem is lines are expensive so won't happen in our lifetimes. Also, even as a native Londoner, I'd rather Manchester got a fully underground heavy rail system before London got any more lines

2:15 Jago found the keys to the reading room and the neighbourhood of Chelsea better take cover 😂😂😂

I seem to recall that when the Jubilee Line was built, there was concern about it passing very close underneath the foundations of the apparently very posh Royal Automobile Club in Pall Mall. This was satirised as worries about "a member diving into the swimming pool and ending up in Neasden".

Surely there will be a Yerkes Line. The colour should be Asparagus Green.

As the Jubilee line took on the Stanmore branch of another line you could argue that it wasn't COMPLETELY new too!

There is actually a tube station IN Chelsea: it's called Sloane Square.

London needs a Monorail!
Ooooh - how about an underground monorail? Now there's an idea (not a good one, but it's an idea none the less)

Re the Overground, I personally think the best solution is to turn it into an S-Bahn style system operating all suburban services with the majority of station stops within Greater London. Only really relevant to the last part of the video though.