From my experience there appears to be a line that crosses England from West to East. We have lived half a lifetime south of the line and half north. We travel north to south regularly to visit family and have walked extensively in both halves. When walking north of the line, those we meet coming towards us share eye contact and a word or two of greeting, a ‘good morning’ or ‘good afternoon’ and perhaps a comment on the weather. Those we meet south of the line avoid eye contact and any attempt at a friendly word is studiously ignored.
I think this will change. I have noticed that the younger generation north of the line are now copying the ways of the south folk and hence the line will disappear and the country will uniformly adopt the stranger-danger attitude and studiously look away in tight lipped silence.
Perhaps an app could be developed that allows users to detect someone approaching and a word of greeting typed, or selected from an appropriate icon, thereby allowing stranger interaction without raising an eye from the screen.