The article introduces main results of a research about defining parking needs to land use functions on the principles of sustainable mobility. Objective of the research was to find a method of determining differentiated, realistic (and environmentally friendly) parking standards applicable in the practice of urban planning and traffic design. Process of the work is briefly presented. Existing Hungarian practice of determining parking demands for different land use functions and zones is dealt with, pointing out problems, inconsequent issues and necessity of an urgent review. Factors to be taken into consideration (land use type, location within the city structure, accessibility and service level of public transportation system, simultaneity of usage land use zones, etc.) are listed. A model for calculation of realistic parking needs is shown. Needs and possible directions of further research are explained.