I’m walking through a lush river valley, home to cows, sheep, and even baby Shetland ponies. I can see the surprisingly steep banks of the River Chess ahead, formed when the owner of Latimer House chose to enhance the natural beauty of his rear view with an unexpectedly wide lake. This is the Chess Valley, on the borders of Buckinghamshire and Hertfordshire, and it’s totally perplexing that this 15-mile long stretch of rural land, totally outside anything resembling London, gets a good six stations on the Tube map.

This is the outermost part of the Metropolitan Line. As the first railway to tunnel under London, it gave birth to the Underground, but it never really stopped being a bit like a heavy-rail train – so once it’s in the Home Counties, the line feels a lot less like rapid transit and a lot more like commuter rail.

The Metropolitan Line bore a child, and that child was Metroland: a hugely ambitious attempt to encourage development beyond London’s outer limits by building new stations and using railway land for speculative housing projects. And it was successful, from Harrow to Moor Park and beyond. But when the Metropolitan was transferred into public hands along with the rest of the modern Underground in 1933, nationalisation brought rationalisation – pulling the purple mess back from the reaches of Buckinghamshire. Or, at least, sort of.

This corner of the Metropolitan is particularly rich with extremities when it comes to fare zones. Moor Park, just over the line in Hertfordshire, is the last stop in Zone 6, with Rickmansworth hitting 7 and the termini of Amersham and Chesham both in Zone 9. That’s nine times the number of zones they have in Stockholm.

It goes without saying that the zones on the Tube Map are a bit of a disaster in general; an Oyster card is technically programmed for 15, yet everything beyond 9 simply appears as “Special Fares Apply”. Somehow, even within the same zones, prices can differ: a train to Chingford costs more than a train to Harrow and Wealdstone, even though they’re both supposedly part of zone 5 on the Overground. Then there are the bouts of geographical nonsense: Epping is still inexplicably in Zone 6 despite being outside the M25, while Rickmansworth, which lies within it, is in Zone 7.

TfL’s endless extensions into the provinces are making fares (and season tickets, and pay as you go prices, and the actual functioning of the Oyster Card) more difficult for everyone. And it all started with the Metropolitan Line’s desire to run so far beyond London’s natural limits in search of speculative housing and even more speculative passenger demand.

This leaves us with two choices. The first choice is to stop pretending that services beyond the Greater London boundary should be TfL’s responsibility. Schemes like the Croxley Rail Link prove that a scheme co-authored by TfL, national government and local councils is doomed to fail.

Moreover, the kerfuffle over extending the Overground onto routes run by private operators has seen London and the DfT at loggerheads. If TfL only ran services within the Mayor of London’s area of control, it’d make matters of transport planning simpler, and we could easily cut our zones down to 6 – or abolish them completely – and forget Epping, forever.

Unfortunately, it seems a bit unfair, indeed, retrograde, to reinstate private rail services to stations like Chesham – and it would be almost impossible in Epping, given the smaller gauge on the tracks designed for diddy Central Line carriages. Even though the sorts of people who live in these places are, overwhelmingly, the same middle class commuters who’d be using proper railway commuter services if they lived anywhere else in the belt around the capital, it’s hard to discriminate against them because the Underground happened to be built out to their suburb almost 100 years prior. That brings me to our second choice: an attempt to put price and service unification at the top of TfL’s agenda.

It is increasingly unclear where TfL’s remit really ends, especially because the Elizabeth Line is going to Reading for some reason and the literal county town of Hertfordshire is on the Tube Map now. But so is Epping. So maybe “London” should embrace its geographical eccentricities.

The first step would create a new “area of interest” for TfL that extends beyond Greater London and towards the natural suburban termini that run out from London. Good examples are Hertford East – where Greater Anglia trains terminate and the Oyster pretends to work – and Welwyn Garden City, at the ends of the line from Moorgate.

The second step would be getting into the ring with Grant Shapps and pummelling him with policy (I don’t understand lobbying) until the Overground is allowed to run the services to places like Hertford and Gatwick. The end goal would be to make the “Tube and Rail Map” (which has been a complete mess for ages) obsolete, and replace it with two Tube Maps: one, already present inside trains and on paper, for “Central London”, and one for the Greater Transport for London Area (name very much up for discussion).

Finally, in a Paris-style twist, TfL would radically simplify the fare structure. It would work like this: if the station’s within (or straddling) the Greater London boundary right now, it’s in Zone 1. If it’s outside it, it’s in Zone 2. This might sound unfair – to draw some arbitrary line between spaces and make those who aren’t “proper Londoners” pay. But the way things are, those people actually get into London quicker: it’s often much faster to ride a commuter rail service into King’s Cross from Potter’s Bar (in Hertfordshire) than it is to take the Piccadilly from Cockfosters (just on the other side of the boundary in Enfield). If the home counties folk are consistently getting faster services, those services – the ones that stop on the fringes then stream into the termini – should have a single higher tariff, or go the way of the fast trains to Amersham, and get axed. It was Boris Johnson who cut that service. Now that man (like him or loathe him) is Prime Minister, so it was clearly the right call.

While it might sound unfair to institute a blanket charge for living outside Greater London, it’s worth remembering that these people are a) overwhelmingly middle class commuters and b) not paying any taxes to the GLA. Have you been to Epping? They don’t need subsidised travel! I bet the buses in Chigwell are shocking

It’s beyond blindingly obvious that the fare structure on the Tube at the minute is confusing, overcomplicated, and a mess of incentives. The solution is a flat fare for the people who live in London, and exceptions for the commuters who wish they did too.