City-based tech tends to be functional. It can get you places on public transport (Citimapper). It can order transport for you (Uber). It can even alert you to other vehicles before you see them

But the annual Playable Cities conference, held this week in Bristol, doesn’t focus on functionality. Instead, the conference’s central idea is that urban technology can be, well, fun. Its centrepiece is the £30,000 Playable City Award, which goes to the designers of a whimsical technology installation of the judges’ choice. And this year, as last, it goes to a project involving novel uses of street furniture.

The premise of “Shadowing”, an installation by designers Jonathan Chomko and Matthew Rosier, is as follows. Streetlights record the shadows of those passing underneath them using infrared technology. Then, later that evening, they project them back onto the pavement, to the amusement and/or terror of subsequent passersrby.

The designers also encourage pedestrians to seek out the lights and do something unusual – hop, dance, wave, the Macarena – to liven up the projections and communicate with future pedestrians. Here’s a trailer:

Using the prize money, Rosier and Chomko will install the technology in eight Bristol streetlights, which will be up and running from today. The installation will also tour other cities around the world. 

The pair say:

Our goal is to create unexpected interactions between people who share an urban environment, by placing pockets of memory throughout the city that remember those who have passed through, allowing citizens to interact through time.”

Other nominated ideas included “Press Play”, interactive music panels in public spaces; and “VVTC”, souped-up security cameras that move, flash or make noises (this sounds, if anything, even spookier than the Shadowing installation).

The Playable Cities conference is currently streaming live here