Based on the vision that Norrköping should be world leading actor in sustainable city development we performed the research program of Hållbara Norrköping 2010-2013. The program focused on how infrasystems contribute to sustainable development through facilitating for the people of the city to live more sustainably. Research dealt with the functions of living, transports and working. The program revealed that Norrköping is a good example of sustainable city development in many regards but that many challenges remain to be addressed in order to become a world leading actor in the area. The most central remaining challenges refer to broadened and deepened collaboration between different actors in the city.