Imagine that you live in a medium-sized market town. Perhaps there are 9,000-12,000 inhabitants. That means there is a high probability that there are around 6,500-7,000 fossil-fuel-burning vehicles chuffing around in an area of roughly 1.5 square miles.
OK, you'll point out, but they aren't all on the road at once. True enough, but perversely there will be more gas-guzzlers in rural towns than in major urban conurbations. Especially if they are affluent.
And you thought you's escaped the big smoke to live in a bucolic paradise.
There is another way.
The average town of this size will take 20-25 minutes for an average walker to traverse from one extremity to the other. That means 10-15 minutes to walk from an extremity to the centre. If you use a bicycle, that will come down to roughly a third of that for an unfit cyclist.
So we're talking about less than 7 minutes to get anywhere in the town and 3-4 minutes to get to the centre. If you drove it would take a minute or two to park the car and you'd be missing out on the sociability and health benefits of being out there in the open.
For wheelchair users the latent time and effort to get the chair in and out of a vehicle at either end would be pretty off-putting, too. So the benefits of being out and about in the fresh air are lost to many people who most deserve them.
Confirmed car addicts will point at horrible road surfaces and unsafe routes. They will have a point.
Which is why we have to start now to correct those things. It doesn't have to be like that. If we have the will we can make it happen and turn our towns into healthier and nicer places in which to live.
Coming next: How we can achieve this with the 15-minute rule in town planning ...