If the members of Boris Johnson’s cabinet do soon decide to give the green light to HS2, I hope they know what they’re doing. I hope they realise the extent to which the high-speed route, in its current configuration, will mainly benefit London and only make the north-south gap and all the divisions that come with it worse. It’s likely they already know: the project exemplifies all that’s wrong with a transport policy that treats mobility solely as an economic engine and commuters as its fodder.

Britain’s transport infrastructure is extended and maintained with one thing in mind: economic growth. Where there is more transport there is more growth, and where there is more growth there is more transport, which is why London and the south-east enjoy a diversity and frequency of transport forms that people living outside it can only dream of.

HS2 is a prime example of missing the point of what transport investment ought to achieve. The spindly, slow-growing spine of HS2 is puny by comparison to the combined choice offered to Londoners by tube, tram, overground, buses, light rail and (eventually) Crossrail. Having an HS2 spur to Wigan is not suddenly going to make it easier to get around Greater Manchester, or indeed, send Londoners rushing to the north-west.

The HS2 plan for Birmingham, where the first phase ends, centres entirely around making Birmingham a commuter city for London, and making its city centre attractive to blue-chip companies priced out of the capital’s real estate. For a city like Birmingham – young and super-diverse, yet leave-voting – having its purpose redefined as an extension of the metropolis will only reinforce its ongoing identity crisis, while doing nothing to improve the experience of living there.

That’s not to suggest Birmingham doesn’t collude in its own degradation. Already, the city council has churned up much of its city-centre green space to accommodate a new HS2 station half a mile from New Street. On visiting the redeveloped New Street station a couple of years ago, the town planner and writer Adrian Jones noted that “the scale of change at times looks like a frenzy of self-harm, the city having lost its memory but still holding to its psyche of naïve optimism about the value of newness, thereby condemned to a perpetual cycle of destruction”.

When Zarah Sultana, the new MP for Coventry South, described living under “40 years of Thatcherism”, this is what she meant. My chief memory of the New Labour years is a constant awareness of the pressure to be productive: yes, there were more buses and trains, but they were there for you to squeeze more work and more consumption, and therefore more baseline economic growth, into the day, rather than more enjoyment. Better transport was about “increasing employability” and not reducing isolation. No one was encouraged to enjoy their lives at a pace with which they felt comfortable: the enforced acceleration of daily life began in the 1980s and has continued apace ever since.

It’s a model that doesn’t work and never will. Researchers from Manchester Business School criticised Manchester’s “misguided approach of developer-led regeneration” for failing to address how “transport and housing is failing communities in the outer boroughs”. To put it bluntly, skyscrapers mean nothing when you can’t get out of Salford.

Mobility is a fundamental need, and it is as much a part of the foundational economy as housing and healthcare. Instead of recognising this, 60 years of transport policy has defined any travel that isn’t commuting as a sort of optional bonus, a desire to be fulfilled chiefly through private car ownership.

There have been brief and notable exceptions to this: for instance, when Barbara Castle, Harold Wilson’s transport minister, redefined railways as a social good and saved the network in the process. And there were the glorious years of the early 1980s when councils actively defied central government to run municipal buses as a foundational service, charging pennies to use them.

This, of course, is how London’s transport is still run: highly regulated, with heavy subsidy, the cheap fares encouraging people to travel into the city to make and spend their money. The rest of the country is denied this and given the promise of HS2 instead, as though a high-speed link to Euston will help you get to the doctor’s.

Yet with a relatively small degree of improvement to the transport network, both within and outside London, people’s lives can be utterly transformed. Hackney Community Transport, an inspirational bus company (yes, such a thing exists) dedicated to “competing against loneliness”, offers a hail-and-ride bus around the estates of Hoxton and Islington to friends, shops and surgeries for £1 a trip.

In Liverpool and Leicester, Arriva is trialling “demand-responsive” buses that enable passengers to share fares and travel door-to-door to places not served by the usual routes. Equally, electrification of the Transpennine rail route, and comparatively low-key projects such as restoring a fast connection between Manchester and Sheffield, would restore what Castle called “the boon of mobility” to people and areas where high-speed rail is less of a priority than simply being able to get to work on time.

HS2 isn’t by definition a bad idea: a non-stop London to Scotland line would help kill off domestic flying. But it’s a project with the wrong principles at heart. Mobility is about so much more than the economy: for one thing, it’s about social connection. Extending the right to fast, cheap, decent transport should be at the heart of what government does, because getting around is something you take for granted until the day you can’t.

• Lynsey Hanley is a writer and the author of Estates: an Intimate History and Respectable: Crossing the Class Divide