A well designed pedestrian street can host lots of different events. There can be official events, sponsored by the city hall, and improvised events, organized by street users. An example of unofficial event is the flash mob:
(video: thierryweber.com)
A Flash mob is a good test to check the status of a space. If the space allows flash mobs, it can be considered a truly public space.
(video: improv everywhere)
[...] video shows a classic of flash mobs, the Free Hugs Campaign, and shows us how the flash mob test reveals the different visions of public space carried by different actors: police officers viewed [...]