The 4th edition of this standard work on Railway Signalling and Interlocking provides the current state of the art. Compared to the previous version, almost all chapters have been updated to reflect new developments. And for the first time, an own chapter about cybersecurity in railway signalling has been added, a topic which becomes more and more important nowadays. Altogether, the book contains the following principal topics: - safety - railway operation processes - interlocking principles - train and obstacle detection, points and signals - interlocking and line block systems - remote control and operation technology, as well as the organisation of operational control centres - safety and control of shunting and marshalling - level crossings - hazard alert systems - product and solution security for railway operations The book combines the knowledge and experience of more than 20 international experts from universities, railway services and the industry. It offers basic knowledge and practical help for railway signalling technicians, operators and manufacturers, as well as for students, lecturers and scientists at universities. It is also a useful source of reference for everyday work. Bonus for free: The e-book-PDF of this book is available upon registration. Users of devices with a PDF reader will have electronic access to all content through a search function.