Are residences near highways, perhaps farther from certain other things, like city centres? Such that a certain type of person (people with pre-existing [perhaps subclinical] mental issues of the type that might make them want to avoid people) would be drawn to live in these residences more than others?
To me, “living near a highway” sounds a lot like a euphemism for “living in the middle of nowhere”, since by definition all arterial roads connecting “somewhere” to “somewhere” through “nowhere” are highways. If you live somewhere isolated that’s accessible at all by road, and you don’t have the budget to build your own long stretch of lane out from the highway, then presumably you live on a highway.