When I first started driving taxis, a piece of advice was proffered by somebody who had been in the business locally for longer than I had been alive: never to talk about religion and politics with my passengers.

It is advice which I have pretty much consistently ignored, for all of the years I have been driving since then, principally because they are usually the two most interesting subjects of all. Of course, with people I have never met before, I don’t initiate conversation – I always wait for them. And sometimes, beyond the initial pleasantries and opening gambits about the weather, what time I am 'on ‘til' and 'been busy?', we even sit in silence for the rest of the journey.

With most reasonable people, the desire not to be seen to be causing offence is quite strong. So it was the other night, in an online discussion about driverless cars – a subject about which I obviously do care, as this technology could one day in the next decade put me out of a job.

One of the tweets was prefaced with 'I don’t mean to cause offence, but…' A reasoned, well argued opinion will not cause offence, whether I agree with it or not, especially when it emanates from someone I know in the real world to have a background in the subject concerned. What’s much more offensive is not to have an opinion at all, as it invariably indicates the person doesn’t care.

"I might be proved wrong in about ten years or so," I wrote, "but I doubt an autonomous vehicle will be able to love another human being enough to use their instinct to be able to summon help for them when they are in trouble."

As these tweets were bouncing backwards and forwards between taxi jobs, a much more problematic situation was rapidly developing, as the first customers emerged 15 minutes late from a party.

Although 20 minutes’ tolerance was built into the schedule, it set the tone for everything going downhill from there, as a series of jobs was booked up until 1am and a subsequent customer then required a stop to be sick by the side of the road. Every job in the series then ran between 15 and 30 minutes late.

That is no good for those customers and ultimately no good for my business, as it gives them the impression that I am unreliable. In nine years of taxi driving, it has rarely been the case that where I have turned up late for a booking, it is my fault. It is invariably circumstances beyond my control, like traffic, or a customer in need of a stop by the side of the road.

But I do always offer an explanation and an apology. Most people are content with that. If they are not, they tend not to say, for fear of causing offence. Rather, they just won’t book me again.