Taxi drivers are a pretty diverse lot. Most of them enjoy a friendly chat. Some of them are really interesting with the added bonus of having a wry sense of humour, and I often learn useful snippets of information. But some drivers can be quite morose.

I use London taxis frequently and always make an effort to make some contact with each one. If they look sulky or uninterested in me and where I’m going, it becomes a challenge to change their mood. Take last week. I gave the driver a big smile as I asked him to take me to Mayfair and he just nodded. As I stepped into the taxi I said a cheerful ‘Good morning’, and didn’t even receive a reply. So I added, ‘Now what’s made you so grumpy today, when the sun’s shining?’

Yes, I know I take the risk that I will receive a short sharp retort but it’s a risk worth taking. This taxi driver immediately gave me a wide grin and said, ‘Sorry, love. I didn’t mean to be.’ We proceeded to have a stimulating talk about setting the world to rights – often their favourite subject.

When they ask me what I do and I say I’m a writer they are almost always impressed. One said, ‘I had one of you romantic writers in the back of my cab the other week.’ I asked who it was. ‘Katie Fforde,’ came the unexpected reply. ‘I know her,’ I said, delighted. ‘She’s lovely. And a best-selling writer, too.’ He was very pleased he’d met someone so famous!

I always ask very politely if I may leave one of my bookmarks on the back seat. (You never know who might climb in after you’ve vacated.) This would be awkward if I’d remained silent until I got to my destination. But by now we’re old friends and without fail they say, ‘’Course you can, love.’ If I haven’t already told them what it’s about they usually ask me, and have occasionally ended up buying a book there and then. (Every published writer should carry a copy of her latest book at all times.) If I really like them and they seem genuinely interested, I give them a book instead of a tip. By the time I’ve done the honours and signed, there’s a good chance I’ve missed my train. But I’m not grumbling.

At the moment I’m promoting Seller Beware: How Not To Sell Your Business, which is probably more appropriate than handing them a romantic novel, as taxi drivers still tend to be male. But this is what happened the other day when the driver dropped me off at Charing Cross station.

‘May I leave a bookmark of a book I wrote which was recently published?’ I asked.

‘Not this one, is it?’ he swung round in his seat and held up my Seller Beware bookmark. I was astounded. ‘Out of all the 22,000 cabs in London,’ he parodied in a dreadful Bogey accent, ‘you have to ride in the back of mine.’

We burst out laughing.

‘I’ve given away about 30 Seller Beware bookmarks to London taxi drivers in the last year,’ I said, ‘so what are the chances of that happening?’

He drove off, still chuckling.

I love these brief encounters. Now all I have to do is make sure I get a smut in my eye before I step into the next taxi and hope the driver’s got a clean hankie, ready to whisk it out! Who knows where that might lead me!