After hundreds of thousands of years on the great pinball machine of evolutionary history the human body has developed an astonishing 10,000 moving parts. These range from the great nether levers, which were clearly formed with the invention of the bicycle in mind, to the tiny muscles in the human nose, which allow us to sniff the difference between 10,000 odours.

The grand finale of all this evolution has yet to come, but the sad fact is that the average cyclist riding through traffic sniffs in just the one acrid, all-enveloping cocktail of traffic pollution. Car drivers sitting in traffic breathe in the same stuff, but have far fewer of their 12,000 muscles in operation at the time. Cyclists' exertions help their lungs deal with exhaust poisons more efficiently than the static body of the motorist.

So how, after millennia of evolution, are we so stupid? How have we ended up with a situation in which our bodies sit in long, slow-moving lines of harmful metal boxes for large parts of the day?

My own theory is that our predicament is because our powers of logic are constantly being outrun by the basic animal drives that nature has given us for survival. These drives are cleverly activated and manipulated by those who have something to gain. The more glamorous the image, the more basic the drive which is activated, but there is little essential difference between the wastefulness of our car culture in Europe and the overgrazing of land in some parts of Africa, caused by unnecessarily large herds of cattle being used as tokens of male power and potency and as marital gifts. The Western world has simply developed more effective forms of stupidity.

In terms of road transport we consume more than most of us think. We consume land, amenities, fresh air, wildlife, communities, health, lives and the long-term viability of the human race.

Unfortunately, the mass of humankind has little control, and little ability to understand what is really going on. Industrialists, telepersons and politicians sing the songs of persuasion, giving us more and better arguments for consuming more, leaving the difficult questions for some other time.

Politicians know damned well what damage is being inflicted by their deliberate avoidance of a transport policy. They know the social consequences of the projected doubling of traffic, and are not going to flinch. The more they deliver consumption the more they increase their power, which is what politics is all about. The standard politician's excuse is that an unbounded car culture is the people's democratic choice. But the market is rigged. And the destruction of our environment should never have been a market matter in the first place.

Most adult cyclists are car users, for reasons of practicality rather than prestige or love of consumption. As cyclists they have almost certainly worked out what is going on, and use their vehicle far more than they want to. But they conclude that to do without a motor car in a car culture would make them ineffective as functioning members of our society.

When I lived in the Scottish Borders I met a chap who described how, 50 years ago, the young people of his town would cycle ten miles down the road to a Saturday night dance in the next town. There would be fifty or so cyclists on the road, and the ride was part of the evening's fun. These days few young people in such a rural area would be seen dead getting from A to B on a bike. It is not a status symbol which finds you a mate. People in the Borders spend an enormous part of their very low incomes on a car, almost any car, to get them to work at the chicken farm or to the supermarket in the next town. Once you've got your car, why risk your image by cycling to a dance? Why pedal on a road made dangerous by your friends driving home along the same road, from the same dance, with eight pints of Younger's Heavy on the accelerator?

The Prime Minister's recent eulogy about the idyllic Britain of cricket matches, warm beer and old ladies cycling to church was an exercise in barefaced hypocrisy. The more things fall apart the more ridiculous is the soothing imagery of the politician. The media are happy to pitch in with their own odes to madness. The Observer, for example, says that just before his sudden death racing driver James Hunt 'revealed he was broke and took to riding a bicycle.' Or maybe James Hunt rode a bicycle simply because it made him happier in his final days?

In evolutionary terms, and, ironically, in terms of the selfish need to survive, the cyclist comes off best. The 1992 report by Meyer Hillman of the Policy Studies Institute estimated that an active cyclist has a level of fitness equivalent to that of a person ten years younger, and these years gained by good heath outweigh years lost in cycle accidents by a factor of 20. In other words, cycling is safe, but mankind isn't.