The renowned and easy-to-use TRAX computer program is back. Author Jeff Geary explores the possibilities of controlling a model railway in prototypical fashion, using operating points and signals from a signal-box style lever frame. Mechanically interlocked frames ensure that trains can only be signaled when the correct route is set, and that conflicting routes cannot be set at the same time. This new book also explains the principles of signaling, the different types of signals and their significance, and how a typical track diagram would be signaled. The application of these principles to the model railway is then discussed. Included with the book is a CD containing the third version of the TRAX program. Additional facilities available in TRAX 3 include new track formations, such as scissors crossings and transition curves, plus extended drawing facilities. Also included in the program is a scripting facility to develop and test timetabling, and utility programs to make it possible to test locking on the lever frame.