[continued…]

Trixy's next call comes 10 minutes later, while I’m still on the Westway: the customer wants to know where I am.

She calls again while I’m crossing Wellington Road and once more as I pull into the side-street where I’m meant to be.

The passenger, an Asian woman in her late 30s, is waiting on the front steps, a phone in one hand and a baby in the other. As she straps a baby seat into the car, she tells me I’m 15 minutes late.

She arranged the cab with Mike two hours ago – she says, using his name – because her baby is sick and must not miss her appointment with a specialist doctor.

Consulting my watch I find I have taken less than 15 minutes to get here, so I was late before I even started, as Trixy must surely have known. But there’s no point arguing.

I face the classic driver’s dilemma: how to drive at speed without making the passengers – in this case, a sick baby and her mother – feel uncomfortable.

I’m not sure how I pull it off, aside from adopting a grimly determined expression, but when we reach the destination we’re on time (so perhaps Trixy knew what she was doing after all).

I tell her the fare is £5.40 and she gives me £7. Hurrah.

More generally, tips disappoint

With deliveries, I expect nothing and that’s what I get.

On account jobs, passengers who have signed a log sheet on behalf of their business prove consistently reluctant to tip from their own wallet or purse.

And on cash jobs, though some people surprise you with their generosity (the mother with the sick baby) others turn out unexpectedly mean (a chatty musician who, when I deliver him to Euston with his cello, gives me zip).

It only takes a couple of missed jobs – missed because I’m not where Mike wants me – for me to start lying about my position.

According to Trixy, all drivers make “false calls”. But fellow driver Lawrence says they’re not a good idea.

“Let’s say he [Mike, over the radio] calls for drivers in Swiss Cottage and you’re at Gloucester Place. You tell him you’re on Avenue Road, but you still might not get the job – which might be a bad job anyway. And if he then calls for St John’s Wood, you can’t tell him you’re there, can you? But that might be a better job.”

Another driver, Frank Agyekum, advises me to position myself by Swiss Cottage in the mornings: this gives me a head start getting into town and if I need to go the other way the roads will be clear.

Later, he says, when traffic starts flowing out of London, you’re better off waiting up the hill.

The worst thing about this job is the waiting.

Nearly all journeys either start or finish in NW3. This means drivers spend half their time empty, either coming or going. Earning nothing.

And with work drying up recently, you can sit around for ages between jobs. But you always believe the next job to be imminent, so you switch on your hazards and rush into caffs to drain cups of painfully hot tea – to find you didn’t need to hurry because the next job doesn’t come up for two hours.

On night shifts, I drive back from jobs with the heater on full-blast: this warms the cab and makes me dozy, allowing 15 minutes of sleep before the car turns into a fridge.

During the day, I kill time flicking through Private Hire & Courier. On the news pages, I learn that when vehicle licensing kicks in next year, my Mondeo – of all cars – will fail to meet exacting rules on the height of front passenger seats.

On the letters page, a correspondent writes that he recently lost a lawsuit against Westminster council over a £20 parking ticket incurred while popping to the loo. Another says it’s hard to earn, after expenses, more than £45 in a 10-hour shift.

“We are all only an accident or engine-rebuild away from ruin”

He may be right: on my first day, I drive 63 miles, more than 12 hours, for a total of £68.90, before expenses.

Over the following days and nights, that hourly rate does not significantly improve. Frank reckons he takes about £80 in 10 hours (of which £20 goes on fuel). Lawrence says he once, exceptionally, took £130.

But he’s been doing this for years and he has many private clients.

Just to break even, I’m going to need a lot more work. So where is it? Why am I always idle?

I see why drivers, susceptible to neurotic self-doubt as isolated workers can be, become convinced that their controller is giving all the work to everybody else.

(“Drivers!” says Trixy. “They’re paranoid! They’re always whining. All day I hear the sob stories. Customers tell me, ‘You have such lovely drivers.’ And I think, ‘Which ones?’”)

“It’s an easy job to get into,” Ferguson told me before I started, “but hard to get out.”

Why? “Because nobody can sack you. There’s nobody paying your wages, you’re earning your own money.”

In fact, Trixy tells me she has occasionally sacked drivers (for overcharging). And she believes that many drivers, currently claiming state benefits, will get out rather than submit to licensing next year.

Towards the end of my stint as a driver, I pick up a character with spiky hair at Belsize Park.

He doesn’t say a word till Ebury Street, in Belgravia, where he stops me outside a restaurant and hands over £10 before climbing out. So I put the money in my pocket and call back to base.

This being Saturday night, there’s already another job: a couple to collect from the opera on St Martin’s Lane. Can I be there in 10 minutes? Sure, no problem.

But then the guy with the spiky hair climbs back in. Sorry, he says, wrong restaurant, can you take me to the other end, please?

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