Is terror forcing you off the Tube?

Yes

When I first moved to London more than a decade ago, I used to love the Tube: its rackety efficiency, its creaking grace. From the Circle to the Central line and the Jubilee to the Piccadilly, I thought it the only way to travel. No longer. These days, I am emphatically a bus person (when I am feeling flush, I am also a profligate taker of taxis).

I could not tell you how much a weekly Travelcard costs. So far as I'm concerned, an oyster is still something you eat with tabasco and a glass of something chilled. I now go by Underground so rarely that, to my amazement, I am prone to getting lost in the warren of tunnels I could once have walked in my sleep.

Like everyone, I used to hate the overcrowding, the constant closures and breakdowns and, in the summer, the terrible, crushing heat. But I put up with them.

Then the warnings about terrorism grew more frequent. I noticed that I was tense the moment I walked through the barriers; that my heart beat all the faster as I stood on the escalator. Should the train grind inexplicably to a halt mid-tunnel, my palms would begin to sweat. Journeys, even very short ones, became intolerable. I could not flick through a magazine, or a read a novel; I was too busy scrutinising my fellow passengers for signs of murderous intent.

I know this sounds lily-livered - that, by changing the way I live my life, I am handing a kind of victory to the terrorists. But the truth is that, in spite of Ken's traffic jams, life above ground is so much more tranquil than life below it.

In the broad light of day, you have the illusion of safety; should you feel uneasy, you can simply jump off the back of the Routemaster and walk instead. Should the worst happen, you might be able to run for it.

But in the bowels of the Underground, you feel like a sitting duck. You have no option but to sit there and wait. The engine grinds; the train stops; your heart sinks. I, for one, prefer not to endure those awful few minutes - that eerie silence - before the train finally lurches back to life and into the next station.

No

There are many, many reasons not to go on the Tube: stifling heat, freezing cold, "extended service intervals", shortened mugging intervals. But the prospect of an attack by al Qaeda terrorists should not be one of them.

It is so easy to be scared. Shabby, shut-in places have always made us fearful, and now, at last, we have what seems like a plausible reason to be frightened. We can all imagine what a test tube of toxin, say anthrax, could do in the slightly larger tube of a London Transport tunnel: no escape for the anthrax, no escape for the victims either. Then there is the famous competence of Underground management and staff. Imagine placing your life in the hands of the people who brought you the Circle Line?

We may rightly be sceptical about the "security sources" who tell the papers they've found yet another plot to target the Tube. We may remark that such stories seemed to peak at the time that similar "security sources" were crying wolf on Iraq. But, for all the hype, we should not doubt the threat is real.

Yet, to avoid the Underground in the belief that this will save you from dying horribly is a mistake. Because unless you opt to stay in bed, you will have to travel in some other way. And in doing so you will deliver yourself up to forms of transport far deadlier, on any actuarial basis, than the Tube. The roads are weapons of mass destruction all the time. Car driving brings a daily carnage somewhere in the UK. Cycling: carnage plus carbon monoxide. A motorbike - you might as well buy the Co-op funeral package now.

You could, of course, leave London altogether, move out to the country, stop coming into town, use Bluewater instead of Bond Street, the local multiplex instead of the National Theatre. If this is what you choose to do, I wash my hands of you - you are dead already.

I spend 30 minutes a day down among the terrazzo tiles - London Bridge to High Street Kensington - an experience of tedium, not terror. With the Tube carrying three million passengers a day, many of them actually moving, you would have to be really very unlucky to be the victim of a terrorist strike. It is like refusing to drive on the M25 because there is sometimes a crash on it. But this analogy only stretches so far - the M25 is a significantly more dangerous place.

The WMD threat should never be overestimated. It is rather difficult for amateurs, without sophisticated manufacturing plants, to kill masses of people with a so-called weapon of "mass destruction". No doubt this is one of the reasons why it has never happened, indeed hasn't even much been tried. The Aum terrorist attack in Tokyo, the deadliest so far, managed to murder only 12, even in the seemingly ideal conditions of an underground station.

What of conventional explosive? There would, of course, be a mass of casualties but the potency of conventional explosive on the Tube would be no greater, and possibly less, than in an enclosed space in a building where walls and ceilings are likely to collapse entirely. Not that this would be any consolation to someone caught in the blast.

Yet if people are scared off the Tube, scared to come into central London, life starts to change and the terrorists have half-won already. There is no need to allow them the victory. As a form of slow death, the Tube is unsurpassed. But it is very unlikely that you will die horribly on it.