There is a new art exhibition showing at Piccadilly Circus Underground station. Yes, really. Few people know about it, certainly not the helpful attendant on the station's information desk, whom I asked for guidance when I couldn't actually find the exhibition in question. "Do you mean the Royal Academy?" she asked.

No, I explained, I had come across the Royal Academy before. I knew my Vuillard from my Victoria Line. This was an exhibition in the station itself. She looked underwhelmed. I showed her a press release from London Underground Marketing Strategy. "Platform for Art is pleased to present a range of exciting new media-based work at Piccadilly Circus," it said. I was sure it was exciting, I added. I just couldn't find it.

"Perhaps it is over there," - pointing to a nondescript corridor. "Sometimes they put pictures up over there." I wandered across to Exit Subway 2. There were indeed some pictures up. Few of them looked, at first glance, terribly interesting. There was one striking photograph, of a lady in a fur coat carrying a Chanel bag, scooping up the waste deposited in a nearby gutter by her fearsome- looking dog. Nice touch, I thought.

I looked at the name of the artist. Pre-emptive apologies to her and her fellow East European citizens if my cynicism is misplaced, but Marketa Bankova sounded, well, unlikely. But to be fair, all the other names sounded reasonable, even, in a certain untainted tone of voice, one Florin Tudor.

Anyhow. The suspect names and their colleagues were part of a project to "expand the reach of the London Underground public art programme, presenting [their work] to a worldwide audience". The images had been selected from their web-based art, using new media and computer technologies.

Well I don't know how many people log on to www.tube.tfl.gov.uk/pfaonline of an evening to enrich their lives, but let me tell you about the audience in Piccadilly Circus.

Most of them, it is fair to say, were no more inclined to look at art than to debate whether you can logically derive a prescriptive conclusion from a descriptive premise. They were in a hurry; they looked unhappy; they just didn't notice the art was there at all. I stood in Exit Subway 2 for about a quarter of an hour. Not one person engaged with the public art programme. Not even a sideways glance; I was checking. They strode purposefully, man and woman, towards the fresh hell of their ride home.

I am very much in favour of public art, bold commissions, new art forms, cutting-edge technology. But they all have their place. I kind of admired this quirky initiative. But Piccadilly Circus? In today's Underground system? Here's a test: if you are a regular user of the London Underground, can you read this following extract from its Platform for Art programme without bursting into tears?

"The site is based on an animated caricature version of the London Underground network. Visitors can select 'journeys' and travel on 'trains' to a series of platforms, each of which represents an artist's work. En route, their bizarre fellow passengers offer helpful tips... " And on it goes.

This is not the space to describe the deficiencies of the London Underground system. Trust me, as a born and bred Londoner who has used it for 35 years: it has become awful. The idea that, on a typical journey, we should a) notice some pallid posters squeezed into one of the busiest stations in the city; b) be inspired by them to log on to a complementary website, which c) enabled us to travel on virtual "trains" to complete virtual "journeys", in the company of d) bizarre fellow passengers, is simply beyond parody.

Public art has a vital function in nourishing our imaginations, and it works most excitingly in unlikely contexts. But I couldn't help thinking there was something grotesque about the aspiration, in this case, of a public body striving so hard to disguise its desperate performance with such flimsy, pretentious diversion. It brought to mind another era, when aesthetic excellence and efficient performance were twin ambitions, never to be prised apart. Charles Holden, designer of the marvellous Piccadilly Line stations of the 1920s, said he had wanted to "create an architecture as pure and true as a Bach fugue".

In fairness, the new stations of the Jubilee Line, among the greatest pieces of architecture in postwar London, would not be embarrassed by that grandiloquent ambition. They work. As design, as public space, in function and in form. They put me, and maybe even some of my bizarre fellow passengers, in a good mood whenever I use them. But art and design should never be used to distract us from logistical limitations. It is putting a very ramshackle cart in front of a very important horse. It breeds cynicism and indifference.

I went down the escalator after seeing the art of Piccadilly Circus Underground station. At the foot of it, an indifferent musician was playing a demented guitar solo. Nobody paid any attention to him either. It wasn't entirely his fault. Art has astonishing power to transport us. But sometimes we want to be transported somewhere else; on time, in comfort, in a real train.

Peter.Aspden@ft.com