I was recently invited to a friend’s wedding in the historic city of Oxford. Wearing our best robes, and with a toddler, a baby, nappies and toys in tow, my wife and I drove from London to Oxford, shunning the alternative of a journey via bus, Tube, train and bus again to the wedding venue. My wife is a keen environmentalist, but not that keen.

On arrival in Oxford, an economic puzzle. It is cheap to park in Oxford’s centre – free, in many areas – but with a maximum stay of two hours, it was impossible to park there for the wedding. I eventually resorted to dropping the family at the city-centre venue and weaving up and down North Oxford’s residential streets for a couple of miles.