At first glance, public transport in the majority of cities and regions around the world would not be considered high-tech by most passengers. However, when taking a closer look at the systems that are necessary to attract/retain passengers and ensure efficient operations, the importance of IT and the high-tech nature of the public transport sector becomes clear. Transport operators use advanced information technology products in order to plan, optimise and manage their fleets and staff. Sophisticated software systems support and drive these tasks. Furthermore, these systems are used to manage daily operations, which includes monitoring and dispatching of rolling stock and crew, providing passengers with realtime information, electronic ticketing and much more. As in many industries, public transport and associated IT standards vary around the world. Several operators have invested significantly in public transport, while others have a great deal of catching up to do. Strategic investments in public transport can significantly improve the quality of life in cities and regions. IT systems play a vital role in supporting this aim. Why write this book? For what purpose and for which audience? Above all, this book is intended for those who develop, implement and operate public transport IT systems. These readers need to be familiar with the software and understand public transport IT systems both at a high level and in detail.  This is achieved through descriptions of public transport business processes and a detailed illustration of a comprehensive systems data model. Furthermore, the book was written for professors and students of transport and IT, at universities and other institutes of higher education. Finally, the book is intended for those in the public transport industry who use these systems and want, or need, to understand the systems in further detail.