The established approach to regulating urban development requires the city to have an approved general plan for development of the city and a plan for regulating construction. However, as modern cities are changing, a fundamental revision of the means for legal and strategic planning is essential. New models for urban planning are being tested through limited interventions or in trial areas, and then, if successful, subsequently expanded to the whole city. Barcelona is experimenting with the size of neighborhoods and partial limitations to the traffic. Poland is reforming the socialist planning system with an emphasis on the feasibility of the plans. Italy is advancing the urban planning approach based on the living rhythms of the citizens.