The Travel-and-Traffic Theory (TTT), reported at the 5th ITS Congress in Seoul, has been developed by application of General Systems Theory in analysis and synthesis of transport and transmission systems. The theory proves to be very useful in better understanding of transport and transmission systems in general, and in definition of National Intelligent Transport System Architecture (NITSA). All basic concepts of the theory are efficiently applicable, giving better insights into the complex relations among intelligent transportation systems (ITS) architectural elements, and between the elements and the ITS environment. Especially useful is the concept of the travel entity lifetime and aging, and the concept of classification of travel-and-traffic systems into two subclasses: the subclass of transport systems, and the subclass of transmission systems, each of them being divided into two further subclasses: travel-in-transport systems and traffic-in-transport systems subclasses for the class of transport systems; travel-in-transmission systems and traffic-in transmission systems subclasses for the class of transmission systems. The last concept reveals the necessity for finding compatible solutions for all four subclasses to enable them to participate in building an effective and efficient national intelligent transport system. Other TTT concepts help to understand the modal aspects of NITSA, especially the clear distinction between the ITS solutions for travel-in-transport modes and traffic-in-transport modes. With this distinction, it becomes easier to classify the basic components of the NITSA. The application of TTT in the processes of definition of National ITS Architectures help in understanding the complexity of ITS solutions, and the high costs of errors that may be caused by late definitions. The need for standardization of basic ITS structures and programs, before they enter the actual national intelligent transport system, becomes more clear, too.
Abstract