Just read this article: How we got Glasgow playing in the streets again
"People still love to play on the street – but sometimes it takes careful design to get them started, as we found out while creating Scotch Hoppers for the Glasgow 2014 Games."
Some interesting thoughts from the game designer, particularly about permission (especially creating permission to speak for itself when there are no facilitators present) and appearance (make a game that doesn't look like it is designed for children, which could put off adults.
Link to the article on the Design Council website: http://www.designcouncil.org.uk/news-opinion/how-we-got-glasgow-playing-...
Videos and more details about the game itself, Scotch Hoppers: