In order to achieve the necessary turnaround in CO2 emissions in the transport sector, clear framework conditions and committed implementation programs are needed. However, efforts to promote a change in mobility behavior largely fail because national reduction targets for 2030 or 2050 are too unspecific for companies, institutions and citizens to develop a sense of personal responsibility and commitment. The project builds on studies that investigate the applicability of sufficiency principles to change mobility habits, e.g. through individual mobility budgets. Previous experience shows that transport emissions could be effectively reduced by limiting the number of certificates for carbon-intensive modes of transport, but would only be acceptable if the individual share of certificates is perceived as fair. The project will combine these findings and available research results as well as existing tools and concepts to test the impact of mobility budgets in real-world application contexts, for example, for the traffic management of employee mobility or for raising the awareness of students and staff of a university campus. Individually defined mobility budgets are used to "translate" long-term CO2 reduction goals in traffic into the concrete current life situation of the people involved by showing short-term, personally achievable goals in line with the national CO2 reduction strategy (see concept from mobalance). The aim of the project is to test the implementation of individual mobility budgets in concrete use cases by combining elements from existing apps and research results into a prototype and testing the behavioral changing effect in a long-term study (min. 1 year) in real test environments. At the end of the project, in addition to the prototype and the impact analysis, concrete business or operator models for the tested use cases as well as estimates for implementation in further use cases will be available.