The public transportation company for Copenhagen and surroundings (HT) is primarily using GIS as a tool in the analysis of travel patterns and in the planning process. An extensive suite of ArcView GIS applications has been developed for these purposes. For modeling of public transportation the Hogia, Sweden, public transportation model has been chosen; currently the focus is on adding GIS functionality to this complex public transportation model. SDE for SQL Server has been chosen as the platform for distributing the data within the organization as well to Internet-based services.