Public Transportation Operators face several challenges to providing efficient mobility services especially in sub-urban environments. Undoubtedly the task of deploying a self-driving shuttle into an existing public transport system on public roads can be regarded as a major challenge for contemporary automated driving systems.  ABSOLUT focuses on narrowing this gap by connecting the Leipzig Trade Fair Area with the BMW plant in Leipzig on a 15 km long route being the first project in Germany to provide a self driving shuttle operating at velocities up to 70 km/h in real traffic. The project closes with four weeks of testing with real passengers showing the capabilities of the vehicle and providing insights on future developments. The article provides an overview on the system architecture employed and  focuses on the automated driving system based on the Robot Operating System and the Automotive Data and Time-Triggered Framework. To ensure reliable operation in diverse conditions a redundant sensor concept with GNSS, LiDaR, Camera and Radar is introduced. Furthermore the article discusses the shuttles localization and state estimation system. As the route contains a high variability of driving environments a combined GNSS/INS/LiDaR fusion system with additional failure detection module is employed. To approve the shuttle for driving in public traffic a stepwise process is defined in close collaboration with regulatory agencies.