Just before Lunar New Year, I went to Shenzhen to breathe some long-needed mainland air - but a few metres across the border I stopped dead in my tracks: an outdoor wedding? At Lo Wu station?

Why else would there have been a long white marquee decorated with flowers and hearts? Then I twigged: it was the caring China Rail that had set up the tent, to shield the five million or so people going home for the holiday from the sun.

On the marquee were slogans such as "Treat travellers like family" but the soldiers (yes, soldiers, not train staff) manning the entrances seemed as brusque and ruthless in driving back the thousands trying to cram into the ticket hall as any conductor.

Normally, whenever I'm near Lo Wu station, I feel an uncontrollable urge to get on a train and go far away but, looking at the heaving tent, I was euphoric to be on solid ground. I knew too well what those travellers were facing.

Once I was travelling by train from Urumqi to Jiayuguan, in Gansu province, a 21-hour journey, the only ticket left having been for a hard seat. The aisles and corridors, even the toilets and baggage racks, were full of people fighting for space.

I waded through the torpid river of humanity towards the person-in-charge-of-train carriage and encountered a queue a car long. After an hour's fight-wait (it's a mainland thing: waiting in line while fighting to keep your place against hundreds of usurpers trying to elbow past you) there was a crushing blow: no vacant sleeper bunks.

Every time a vaguely uniformed person passed through my hard-seat carriage, where I had fought long and hard for the ultimate luxury - a place by the window where I could rest my head on a nail sticking out of a small table - I asked with increasing desperation whether there wasn't a bunk available for which I'd happily pay triple and shine his shoes with my hair. Nothing. Instead, the train person advised me to look after my belongings because many bad people wanted to steal them. But how was I to stay awake all night when the nail sticking out of the table was so soft and welcoming?

Fortunately, the glaring lights stayed on all night and, although asleep, the people in my carriage made just as much noise as they would in the daytime, so I got through probably the longest night of my life un-robbed.

It was estimated that mainlanders made 3.5 billion journeys before and after this Lunar New Year. Poor devils. I'll tell you when is an excellent time to travel in China, though: during the Lunar New Year holiday. You'll have every carriage to yourself.