This book describes analysis of control- and operation diagnostics problems of trams and development of new methods, models and systems. Analysis describes the faults and failures influence to the traffic, their causes, maintenance system efficiency etc. Also it includes short analysis of existing diagnostic methods, algorithms, integration problems of different onboard systems. Practical part of research covers the design issues of new models for tram control, diagnosis and supervision to increase the system reliability, safety, security and passenger comfort. Book ends with profitability evaluation of designed system.