In the “Flexa” project, LVB is testing a mostly self-developed on-demand system that is intermodal and seamlessly linked to regular line-based public transport services. Passengers are transported in a dense network of 128 stops in an area of appr. 13 km² by up to 5 mini buses in total. The next stop is rarely more than 200 meters away. Trips must be ordered in advance by smartphone app or phone call. The system bundles travel requests that are similar in time and space, reducing travel costs and energy consumption (“pooling”). There are no timetables and no fixed routes. Special features of the Leipzig project are the intermodality and the deep integration into the existing public transport system. At a total of 7 intermodal stops at the edge of the service area, passengers can change to suburban trains, tram and line-based buses so that they can reach their final destination conveniently even if it is outside the service area. The entire travel chain is organized by the system. Cannibalization of the regular service is prevented by the system referring to a line-based bus when it is running at the same time on the requested route. Project partners are the Max Planck Institute for Dynamics and Self-Organization in the field of algorithm development, and the Federal Ministry of Transport and Digital Infrastructure, which are funding parts of the project. Until September 2020, more than 50,000 passengers were transported with Flexa, on a working day usually 250-300 passengers use the service. Almost 80% of all trips start or end at one of the connection points to the tram and suburban railroad. First evaluations suggest that Flexa is not only heavily used itself, but also provides for more passengers in regular public transport service.