This thesis examines the potential of transforming Zagreb's central streets into pedestrian zones and zones with more sustainable mobility models. The paper presents various methods of applying the principles of modern sustainable urban planning approaches and the advantages of applying them when designing urban tissues. Based on the analysis of examples of good practice and interviews conducted with experts from the relevant fields of science, guidelines for the implementation of new sustainable urban and transport solutions were proposed. After analysing the traffic and spatial characteristics of the streets within the scope, the streets were classified into three categories, two of which were selected for further, more detailed, elaboration. In further elaboration, an inventory and analysis of the existing condition of streets from selected categories were made through graphic displays. For each category, three possible street transformation scenarios have been created in the direction of achieving sustainable mobility, strengthening the city's green infrastructure and raising the quality of life and living in public spaces. The offered scenarios, in addition to having a positive impact on the social and health component, also have a positive effect on ecological and economic stability and are the key to achieving a balance between the protection and development goals of society and the ecosystem as an inseparable whole.