I thought I should give a nod to the Circle Line, not least for its status as aesthetically the most distinctive element of the Underground map. By virtue of its geography, it's become the latterday equivalent of the old City of London wall, albeit (mostly) just below the earth's surface.
When I look at the Underground map I subconsciously treat everything within the Circle Line as belonging to the city centre, and therefore - if I'm feeling particularly misanthropic - to be avoided. A number of times I've deliberately chosen routes to places that avoid this area entirely, often utilising the increasingly reliable Overground service. This is because I class the Circle Line and what it encloses as being part of work, not pleasure. If I can help it, I'd rather not step foot beyond that yellow stockade when I'm not doing my job.
There's a mindset that operates on the Underground within the boundaries of the Circle Line. It's that of the tourist-cum-worker. It's that of the no-time-to-stop-and-think, must-get-to-my-destination-at-all-costs, always-room-for-one-more-person-inside-this-already-full-to-bursting-carriage sort of person. That's fine if you're a visitor or an employee. If you're a resident or a traveller, staying above ground is always the better option.
If I find I have to visit somewhere within, what for fares purposes, is called Zone 1, I'd rather get off at one of the boundary stations and simply walk the rest of the way.
Indeed, when I worked in Soho, I'd always get off my train at Euston and complete the journey on foot. I came to look forward to this stroll, especially as it took me through the quiet back streets of Bloomsbury, at that time of the morning affably quiet and stylistically fascinating. I miss not having the chance to do it now, though I still, when I have the time, get off the Underground a few stops early and finish my commute by pavement.
That's not to say I never use the Circle Line. If you want to move sideways through the capital, are not near the Central Line, are in no mood for dawdling on foot and are too tired to contemplate any other kind of transport, it's the most straightforward way of sliding east to west and vice versa.
Except, of course, you're not actually using a single purpose, self-contained line.
The Circle shares all its tracks, save for two short stretches between Aldgate and Tower Hill and High Street Kensington and Gloucester Road, with other lines. The bulk of its southern half is duplicated by the District; most of its top half is used by the Hammersmith and City AND the Metropolitan. To this extent, it doesn't exist. It is a line created by cartographers, not engineers.
The titular circle grew out of expediency. Bits of it were built individually, with no intention to be linked into a loop. Different companies completed different stretches, beginning with Farringdon to Paddington. Those stretches creeped in either direction, but with no urgency. The circle took over 20 years to complete, finally becoming one entity in 1884.
But even then it wasn't formally identified as a circle, in the form of a separately-coloured, separately-named line, until 1949. Before then, maps simply showed the respective Metropolitan and District services (although from 1947 a circle of sorts had been denoted by the addition of a thick black border along the route). It had long been informally known as the Inner Circle, but this was never given official sanction.
At the time of writing, this non-existent line will shortly become properly non-existent once again. As early as December of this year, the Circle may become part of a Hammersmith and City Line spiral that begins in Hammersmith, runs to Paddington (along the route of the current Hammersmith and City) and then does a complete loop of the current Circle Line ending at Edgware Road.
I'll talk more about the Hammersmith and City Line shortly. But if this plan comes to pass, and it has been confirmed by the manager of the Circle and Hammersmith and City Lines, it will constitute a logical reconciliation of what has, cartographically-speaking, been a 60-year illogical quirk.
I would not miss the Circle Line in its present form. A rationalising in the shape of a merger with the Hammersmith and City would, in theory, mean smoother services and a more predictable timetable. At present, you cannot rely on Circle Line trains to actually do what their name implies. Orbital services have in-built problems. One single delay can have a terrible knock-on effect. Synchronising with those services running as District, Metropolitan and Hammersmith and City trains is an additional nightmare.
As such you'll be lucky to have a smooth journey around the loop. You're usually guaranteed fairly uninterrupted passage between Baker Street and Aldgate, and between Tower Hill and Victoria. But any route that ventures beyond these stretches will always involve a delay: FACT. You could well end up sitting for at least five minutes at High Street Kensington or Edgware Road, while there's no point assuming anything speedy about Aldgate. If your journey takes you through this station, you must always factor in an extra 10 minutes.
At the end of the day it's all to do with timing. The Circle currently runs seven trains in each direction at seven-minute intervals, with a notional complete circuit mathematically designed to take 49 minutes. But it doesn't. Because of those synchronisations with other lines. Because of mishaps. Because of unexpected delays. And so on.
Unspooling the circle and turning it into a spiral would remove much (but not all) of these inconveniences. I hope it goes ahead, and goes ahead soon. If it stops people treating it like a reason to have fun, then that alone will have been worthwhile.
How to write about a line that doesn't exist, but whose stations you have - to a man - nonetheless visited? In a rambling, hesistant, unpredictable fashion that doesn't, ultimately, go anywhere. Just like the line itself.