Final proof I've cracked my addiction to motoring

As for the car's convenience ... no other vehicle except the private car allows you to pick up and drop off everything, from couture to children to lawn cuttings, with such fierce spontaneity. When I contemplated a life without a car of my own I feared not simply that I would be unable to do everything I wanted to do in the city, but that, like an amputee, I would still find myself trying to flex - or drive - a muscular appendage that was no longer there.

Not a bit of it. The kids walk to school, as a family we mostly use public transport, solo trips I've done by bike for some years. Still, in anticipation of car journeys I hadn't factored in, I joined Streetcar, one of these pay-by-the-hour hire services that have cars parked up all over town. They had three cars within five minutes' walk of my house.

In fact, I didn't use Streetcar at all until this last weekend, and had been seriously thinking of cancelling my subscription. It turns out there aren't any car journeys I hadn't factored in; or, rather, there weren't any I really had to make.

It was strange driving a car in town again after a 10-week layover. Immediately I felt the stress of it descend on me like an iron yoke. I was beeped and sworn at by other drivers, and not because I'd done anything wrong - merely because they were stressed-out too. The traffic was, as ever, unbelievably tedious: sitting listening to crap radio and watching a corner of suburbia is a living death. I was happy to hand the car back.

On the second day we hired a Smart Car for seven hours and drove down to Guildford for lunch with friends. So far, so good, but the strange thing was that conscious of the Sunday evening queues to get back into town, I found it hard to chill out on the lovely North Downs. In the event I had to call the company and extend my rental by half an hour.

It occurred to me that the only real problem with the car rental schemes of this kind is other cars. If only there were fewer of them on the road I wouldn't have to worry about the idiosyncratic traffic when returning my rental vehicle. I began considering the idea of a subsidised system. Sod Paris with its bike hire scheme, why not one for cars? That way the most inveterate private petrol-heads could get their fix, while freeing up central London's roads for other users. Damn it, I should've stood for Mayor after all.