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 (see references). In this paper, a new definition of topological accessibility is discussed as well as other related problems. In particular, two crucial topics are considered i.e. the sense of using parameter omega for weighting the adjacency matrix A and the way of coding of 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.