Towards a new definition of topological accessibility

During the past 30 years the accessibility of vertices of transportation networks has been considered by many authors. In this paper, a new definition of topological accessibilty is discussed as well as other related problems. In particular, two crucial topics are considered i.e. the sense of using parameter ω for weighting the adjacency matrix A and the way of coding the main diagonal of adjacency matrix A. Some important remarks are also formulated. The classification of vertices of a portion of the Interstate Highway System, considered from the accessibility point of view, is presented at the end.