2017 Volume 73 Issue 2 Pages I_33-I_44
Connectivity reliability is one of the indices to measure the functionality of a road network. This is a probability of a connectivity between an OD pair based on a network geometry and passability of its links. If Dijkstra's algorithm is employed to check the passability, the amount of calculations will increase with the order of the square of number of nodes, therefore the applicability to a large road network will be a problem. In this study, an aggregation of a road network with the use of a network Laplacian and adjacent matrix is discussed. “Partitioning” of a road network and “centrality” of partitioned areas are a key point of the proposed method to make a mesoscale network data. Trial calculations on the emergency transportation road system in Shiga prefecture are conducted to check the applicability of the proposed method. The results shows the proposed method shows good approximation of the original network and always provide a lower bound of connectivity reliability.