Welcome, Best Beloveds, to the 8.35am train out of Richmond, Virginia – heading for New York and Pennsylvania Station, one of the very few rail termini to have been demolished in the real world and then reconstructed within Satan's colon. Lately, I have been spending a good deal of time in Penn Station and have wondered – not for the first time – whether 65% of the people waiting for trains there appear to be seriously mentally distressed because they arrived that way, or because they have stepped into an alternative universe of heat, bewilderment, pain and ambient evil. You may be aware that many US rail stations are grand expressions of generous respect to their users, full of stately perpendiculars, handy benches and lots of gold leaf – high-ceilinged temples to mass transit and the communal hopes of a bygone age. Penn Station is there for balance: to remind you that this Depression will not produce a New Deal, and that many members of the general public are surplus to requirements; and to hint that your train will travel at the speed of lazy treacle on a cold day, will shudder along rails that even Railtrack would call poorly-maintained, and will give priority to freight, cars, pedestrians and any animal above the size of a healthy adult woodchuck.

Yet I continue to love American (and Canadian) trains. I am trying to rebrand my debilitating and expensive fear of flying as Steampunk Travel and – at a certain level – I find I am convincing at least myself that rail transportation is a good and lovely, as well as an ecological, option. US trains are roomy, their passengers have no expectations and therefore often eschew UK passengers' lapses into frenzied disappointment and rage when they are delayed, misled, or ignored. Plus, US trains are still rich in the iconic elements that I, lover of black and white movies that I am, find intoxicating. They are monumental: they still roll majestically into stations with their bells ringing like harbingers of strange mortality, they still hoot across the countryside in the manner of wistful mechanical whales, the conductors still wear little round blue conductor's hats and the Red Caps still wear red caps – although sometimes they're baseball caps ... From my first exposure to a real live US train around 20 years ago in California, I have been in love with them. It glided and wailed along the sunset into a wood-canopied rural station full of cicada songs and moist heat and my heart was lost.

Of course, this only slightly mitigates the fact that I am back to business as usual – typing on trains and rattling from city to city, performing readings or the one-person show while trying to keep the novel on track in spite of tiredness and an increasingly cranky spine. This isn't ideal, but life rarely is and I'm up over the 300-page line, which is a comfort: the pages may not be great, but they are there and I can always rewrite a page that's there. I would have to make up a page that isn't there from scratch. Currently, of course, the 350lb gentleman in front of me who is thrashing in his seat, sighing and occasionally exclaiming "Phnnah-urr" isn't helping matters, but I have come to expect this on trains. Trains are where people speak to themselves with loud enthusiasm, trains are where those listening to mp3 players air drum without shame and where those not listening to anything do much the same, and trains are where people eat hot dogs made of reconstituted protein substances illegal in many countries.

I can particularly recommend travel from New York to Montreal – the journey takes around 11 hours for no really good reason, beyond a type of shyness that will leave your train hiding, loitering and then simply fainting to a halt at regular intervals. When you are travelling north it will wait like a faithful lover to meet and be passed by the southbound train and when you are travelling south it will also wait. You will do a great deal of waiting. But you will be beguiled by the autumn foliage (should it be autumn) the picturesque wetlands and gentle vistas – all slightly distracting if you're trying to write a sex scene and are already freaked out by your somewhat intrusive surroundings and the fiddly technical matters you have to consider. Fortunately, you will be able to spot great blue herons, egrets and red-tailed hawks aplenty as you wonder who should do what to whom first and from which angle.

As usual, it's much easier to leave the US than to enter it again. US Border Control began with the usual questions – "Are you travelling for business? How long were you in Canada? How long will you be in the US?" - but then escalated to the kind of enquiries I never handle well: "What kind of writing? Would I have read you? What kind of novels?" I find it oddly difficult to give an adequate definition of literary fiction to men with guns – and yet it's surprising how often they seem to need one. And I am always alarmed when the first option they reach for as a genre suggestion is, "So ... you write romance?" This leads me to believe they are poor judges of character and therefore unsuited to their jobs. On this occasion the interrogation moved forward into areas including, "What about 'Braveheart' - was that accurate?" – which could be a normal conversational gambit, but which seems to develop dangerous significance when delivered in a tone one would imagine should be reserved for poorly-trained drug mules and parrot-smugglers. I had no idea if I was being given an opportunity to prove my Scottish credentials or simply chatting with someone unable to not be violently earnest.

It was then decided that the carriage "smelled weird" – of course, it smelled weird, it's a railway carriage. After a small discussion about whether the aroma was, in fact, "weird" or "just bad", reinforcements were brought in with inadequate tools and a sniffer dog, travellers were evacuated and the next two hours or so were spent hanging about and listening to the noises of a train car being disassembled. Meanwhile, my chum with an interest in contemporary fiction and Mel Gibson loped down the aisle shouting, "Scottish novelist?" in way that led me to be both nervous and hurt that he hadn't remembered my face. I then had to present my passport to be re-checked by a more senior and rather languid official, installed in the buffet car. Arrival by boat is rare and therefore leaves unusual traces on one's passport. I was forced, once again, to reflect on my student days when I had the idea that putting "Writer" in my passport would somehow challenge and unsettle officials of all kinds, prove my interior fortitude, and generally involve me in sticking it to The Man. In fact, I tend to become craven when anywhere near The Man, and The Man, in return, seems to regard my vocation as a mildly amusing indulgence. Writing can, of course, unseat governments, free the soul and prepare the mind and spirit for all possible rigours and joys – but I did not find myself or my vocation especially uplifting as I plodded back from the buffet car to a seriously interfered-with carriage that now smelled both "bad" and "of warm Alsatian".

And now, Dear Readers, as we wait in Washington Union Station, I must leave you. I have a few more days of woodland scribbling to try and get my characters into physical sync and all shiny for the end of their book and then I will begin the long journeys to Oregon and New Mexico. More landscape, more scary food and more sitting and writing … Onwards.