That makes intuitive sense, and when I reasoned about your comment earlier that's the general direction my thinking went.

I live pretty much exactly one mile from my work, and the two nearest shopping centres are less than half a mile beyond that.

I'd definitely be interested in seeing some heat maps of representing this data. It's easy to believe that the majority of people live close to at least one of the places they most often travel to, whether that is a workplace or other activity, and I think you're right that this is an important metric within which to consider such statistics.