Graphic Design Public Installations

For our collab brief we are looking at creating some sort of design/interactive installation that we would put in a public place to see the reaction from the audience.
I have tried to find a few examples of this, i did find it quite hard to find anything relevant but i couple of ideas from it!

Just a few various installations which could generate some ideas for me an my group. i like the idea of pasting something to floor, it looks really effective and eye catching.