A group of researchers of the Lviv Polytechnic National University and "Bucovinian University" are developing the project of intelligent information system to support and maintain the tourist at all stages of his journey - "Mobile Information Assistant of the Tourists" ("MIAT") The book is devoted to the problem of safety during tourist trips and following information support to the tourist. The set of important scientific and practical tasks are solver during the research, they are: developing new mathematical methods and complex of software mobile informational technologies to define the danger level in chosen tourist destinations. The book consists of three main chapters. The first one is devoted to the results of deep analysis of information sources and as a result the main aspects of the research are distinguished. The second chapter describes the architecture of mobile information system "MIAT" to support tourists during the trip. The system contains a subsystem "Safe Tourism", which implements the function of warning tourists about potential dangers. The third chapter is devoted to the methods to make prognoses on the danger level in regions.