This document summarizes an urban prototyping project called "New Nowy Square" that took place in Cracow, Poland from January to October 2017. The project aimed to address problems in a main square dominated by car traffic by testing temporary solutions. This included implementing a new traffic organization, street furniture and greenery. Researchers studied user behavior and experience through interviews and observations during a prototype testing phase. While the prototype was successful and revealed benefits of more livable streets, the project was stopped due to resistance from some merchants and lack of support from city officials. Advocacy continues for permanent changes.