Reliability and Safety Models of Transportation Systems - a Literature Review

Transportation systems form the backbone of economy and play an important role in society. Because of the far-reaching effects of disruptions on these systems (social, economic, national defense), they are classified as critical infrastructure systems. Reliability researches on various elements of transportation systems were carried out since the midtwentieth century. The focus was on vehicles and their components. Infrastructure is an important component of system, in addition to vehicles. The highest level of complexity is characterized by the railway infrastructure. It is natural, that this led to a number of models describing selected issues. In recent years, much attention has been paid to critical infrastructure systems. There have been numerous proposals for the use of graph models in the analysis of resilience and vulnerability of transportation systems. There are many groups of models describing reliability. Some models contain reliability factors only fragmentary. This paper presents experience with reliability models, were tested in research work on the railway transportation system. The inference is not limited to railway transportation system, but generally relates to land transportation systems. The review includes also own models that are dedicated to describing reliability of fixed-track systems, in which processes are determined by a timetable.