Sustainable Urban Mobility Plan -SUMP is a document of urban traffic planning aimed at developing sustainable forms of transport in order to achieve a balance between the dominant use of passenger cars against other forms of transport. Transport science in interdisciplinary cooperation with other fields of science, has reached conclusions in favor of the development of sustainable forms of transport (public transport of passengers, walking and cycling) which achieve better efficiency of the transport system (lower financial and time costs), reducing harmful impact on nature and increase overall traffic safety. Modern trends in transport development seek to integrate the development of all transport forms or modalities, and further implement measures to optimize the entire transport system and services. However, such an approach to traffic planning differs greatly from the previous so-called. “traditional approach ”, for which it is necessary to adjust the existing habits, legal frameworks and rules of the profession as well as to develop some new mechanisms of development and institutional support. Most cities in the Republic of Croatia have just started SUMP projects or similar initiatives that seek to implement some of the measures of sustainable urban development. However, there is still no continued political and institutional support for SUMP to integrate such projects into urban development plans. Also, on the city level, there are a number of disparities between the ways in which several related SUMP methodologies are applied, such as those applied at the European level, as well as ambiguities in the positioning of SUMP in relation to other higher-level strategic documents. Therefore, this paper describes the method of drafting the SUMP through the application of methodologies and the content of each document. The comparison of SUMPs of several cities is presented in order to gain insight into methodological and content differences and the reason for their existence which lies in the need to adapt the methodology to the conditions and possibilities (primarily financial) of individual cities and countries. Examples from other cities also provide an example and experience that helps to create your own SUMP adoption methodology. It is our own methodology (in terms of national level) that is the focus of this paper, ie the way of applying the Eltis methodology with emphasis on the areas of document creation where there are currently problems that prevent adequate creation and application of SUMP in the Republic of Croatia. These problems relate to: Disproportion between the availability of financial and material resources versus the proposed measures and objectives; Inadequate time frame for strategic planning that does not reflect the real needs of the transport system; Limited development of SUMP conditioned by the existing spatial planning documentation; Inadequate position of SUMP in the legal and institutional regulations of the Republic of Croatia; Inadequate institutional support and cooperation between stakeholders Lack of transparency and public education on the concepts of sustainable urban mobility, which calls into question the legitimacy of SUMP. Detecting and eliminating these problems that prevent the creation of SUMPs in accordance with the Eltis methodology, enables the application of SUMP as a standardized document of urban transport development which guarantees the implementation of sustainable transport development throughout Croatia, taking into account local needs and opportunities. In order to achieve such a goal, it is necessary to realize the following tasks that are included in the methodological framework for creating a SUMP tailored to the needs of the Republic of Croatia: Rational proposal of measures in the financial context and fitting into the defined time frame based on adjusted scenarios; Change of the legal framework that allows the creation of spatial planning documentation in accordance with SUMP measures; Appropriate methodology for evaluating the effectiveness of measures; Division of competencies and responsibilities over measures between process stakeholders; Defining a time plan for the implementation of measures; Transparency of proposing measures and defining a precise plan for financing their implementation; Creating an appropriate legal framework that would make SUMP a binding implementation document taking into account local opportunities and the needs of cities; Parallel education of the public, their participation and popularization of sustainable development measures in order to achieve the legitimacy of the project.