Walking in the Melbourne CBD the other day I was asked for directions. Those I gave in a way that humans have been doing so for, no doubt, thousands of years. Something like "See that large building down there? Turn right there, walk for a hundred metres and you will have arrived. There's a cafe next door- sorry, can't remember its name."

In giving directions as I did, I was mentally unstitching my memories of the place that is Melbourne, the identifiable landmarks, the connections, the indelible idiosyncrasies- the image of the city in my mind. Had they asked directions of the person next to me, they would presumably have ended up at the same place, but the route description would have been drawn from different recollections.

Many of those walking past me at the time were pedtextrians. (Those who frequent urban dictionary will recognise a pedtextrian as being someone who is texting while walking, and is completely oblivious to what is around them.) But perhaps some weren’t texting? Perhaps they were finding their way around by using GPS?

Highly influential research published nearly seventy years ago- and still regarded as relevant today- explored the legibility and imageability of the city, the latter being an amalgam of objective city image and subjective human thoughts. With different purposes in mind we select, organise and imbue with different meanings what we see as we continually look to understand and interpret our environment. In that research the physical form of the city image was catalogued into five elements: paths, edges, districts, nodes and landmarks.

In the pre-digital era, it was impracticable to carry maps with us all the time, so instead we used memory of our environment to navigate. If we used maps, those were an abstraction of the physical form of the city. By contrast, if we use our phones- easy to carry- together with GPS directions- no interpretation necessary- we can navigate our way without needing to observe the physical form of our environment or the sensory stimuli which convey the life of the place.

Will the increasing use of digital alternatives to the physical observation and experiencing of our environments inevitably mean we will understand them less? As a result will our mental images of those places be less rich, and therefore our appreciation of their qualities be diminished?

Are our traditional ways of thinking about the legibility and qualities of our environments being overtaken by a new digital abstraction? If so we need to start thinking beyond the physical form and activities of our cities and think more about the impacts and influence of a parallel digital life and interpretation.