In one of his less misanthropic moments, Paul Theroux made the sage observation that all travel is fundamentally circular.
You leave in order to return. But as any inveterate travel junkie (this one included) will tell you, travel is also a disappearing trick, in which you also attempt to carve out a certain amount of time alone, free of the predictable domestic drudgery, the rigours of professional life, and the vicarious diversions that we all use to fill up the time.
No wonder, therefore, that solitary travel appeals to the loner streak that is inherent in most novelists - especially as a journey always follows a straightforward narrative trajectory. Or to put it another way: between heading off and coming back, stuff happens. Which - to state a self-evident fact - is what travel books are all about.
Unless, of course, you're Jenny Diski who - before starting off on the journey under review - actually believed that she could write a travel book "about nothing happening":
I'm not much of a traveller at all. I travel in order to keep still . . . I just want to drift in the actual landscapes of my daydreams, and drifting, other than in my imagination, is expensive. So I concoct the idea of a book about my uneventful drifting. Eventfulness is not the mode of the fiction writer, or at any rate of my fiction writing - events just get in the way. So what a proper travel writer hopes for, I dread: incident. My ideal method of writing a travel book, I realise, would be to stay at home with the phone off the hook, the doorbell disconnected, the blinds drawn.
Now if all that sounds just a tad precious, you're right. Because unless a writer is planning to travel in a hermetically sealed compartment, there's no way that he or she can shut out the outside world. Especially if, like Diski, you've decided to spend several weeks drifting around the US on trains. I mean, who in their right mind expects to sit on an American train for several weeks and not fall into conversation with her fellow travellers - especially given the fact that my fellow compatriots have this predilection for telling strangers their entire life stories five minutes after meeting them.
Then again, don't believe Diski's Garbo-like protestations about wanting to be alone. If this exceedingly canny and most engaging book demonstrates anything, it's that this non-traveller is a damn good chronicler of her exploits on the American rails, not to mention one of those rare discursive writers who can actually draw you into the roundabout workings of her deeply circuitous mind.
Indeed, Stranger on a Train may be an account of two journeys on US trains (one covering the southern states, the latter one following a peregrination into the North Dakota badlands and on west through Montana to Oregon). It may also be packed with incident - like the death of a couple of joy-riding kids in some nowhere Mississippi burgh whose car ended up in the ongoing path of Diski's west-bound express. It may be packed with characters - like a Noel Coward gone-to-seed chap she meets on the Sunset Limited, who launches into a drunken discourse on the existence of pixies. Or the ageing gigolo who offers her his services on her journey across the badlands. Or the sad widower who's going blind and is in the market for a new wife.
And it may also be a damning commentary on the diabolical state of Amtrak, the American railway system - a public utility that, from the Reagan era onwards, has been starved of federal funding and allowed to fall into ruin (because, as Diski notes, "to travel any but the shortest distance by train is bizarre to most people in the States").
At heart, though, this is a book about the sort of ruminations that come to you when cooped up in a moving vehicle for long periods of time. And, most tellingly, it is all about trying to smoke in a society which now considers tobacco to be satanic. Whether describing "the oasis of tawdriness" that is the standard Amtrak smoking car, or being informed that the Californian capital, Sacramento, has banned smoking on its streets (and then discovering that her leg has been seriously pulled), or simply musing on the manifold pleasures of a cigarette, Diski proves herself to be not just a formidable travel writer, but also someone whose near-erotic musings on the dreaded weed almost made me want to take up smoking again. And that's saying something.
Douglas Kennedy's novel The Pursuit of Happiness has just been published in paperback by Arrow. His next novel, A Special Relationship, will be published by Hutchinson in June 2003
Stranger on a Train: Daydreaming and Smoking Around America with Interruptions. By Jenny Diski. Virago. 280 pp. £15.99 sterling