Something that I talked to many people about over the years is their sense of how “dense” (in terms of urban buildup) the country is. This is a subject that can readily spill out into hard political argument—for example, a favoured tactic of those who oppose immigration is to argue that the country is “full” and that there is physically no room for more building. This doesn’t seem to me to be the case at all.
One idea that seems to have promise in explaining this is considering the effect of different forms of transport on people’s perception of their environment. I usually travel by train, and this gives me a certain perspective on the density of the environment. For example, leaving from an inner London train station on an inter-city train I am out of the built up area in around 15 minutes. For most other cities, this time period is around 5 minutes. Furthermore, mainline trains rarely go close to smaller villages. As a result, a journey like London to Edinburgh is 4½ hours of essential rurality; 15 minutes to leave London, then a few periods of 5-10 minutes in the outskirts of a city. Overall, the majority of the journey is spent in open country.
Contrast this with a car or coach journey. It can easily take a road vehicle an hour to get out of London, and many other cities take 20-30 minutes to get in or out of. This makes a huge difference to the perception of people as to how much land those cities occupy. If have your journey is taken up with getting into and out of cities, then you could easily imagine that the country is very dense and urban.
I would argue that my country-centric view from the train is more accurate, as can be seen by studying a map. Despite the UK being a very built-up country, the only map page that looks predominantly urban is that displaying London. Most of the rest show towns and cities sitting in a predominantly green, rural context.
There is an interesting study to be done to see if this is borne out across a large sample; could we correlate people’s estimates of the density of the country against their predominant modes of transport?