Mobility questions our ways of Living in a city. They are linked to multiple social approaches, constrained by the geography of the city and linked to available energy. However, their deployment and their effects in urban space remain little studied as an everyday experience and a factor of activity. The frequentation of the city is mainly observed as saturation or animation and in an abstract and quantified way. But what will the nature of movements in cities, the daily life of 3/4 of the planet's inhabitants be in 2050? The city has grown so much from the intersection of roads that we no longer look at how people cross each other in the squares. What are the speeds, the rhythms, the interactions, the trajectories, the pauses, the sharing in an urban square? Each element in movement draws paths with its own rhythms which are factors of activity and gathering. We propose this exploration on a human scale in 8 cases around the world.