A study on evaluating transportation network based on GIS

Having not considered such aspects as spatial distribution features of transportation networks and resident areas, the spatial influence of outside transportation modes on the features within the research regions as well as the different transit capacity of different transportation ways, the conventional measuring methods based on path analysis and network analysis are deficient to the description of regional transportation situation. With the employment and optimization of the connectivity and accessibility of the network nodes to evaluate transportation network, this study successfully breaks through the limitation of the border of investigative area and, different transportation modes can also be taken into account. Based on the gradually increased correlation coefficient between the connectivity change, which is a gradually increased process from direct connections to indirect multi-steps connections, and the development of regional economy, this paper proposes economy-network diameter index (ENDI), which is employed to evaluate the development of network and the contribution to regional economy of Gansu Province, China with the data of 2002 transportation network and the economic statistics in the Statistical Yearbook. By above methods, this empirical study comes to the following conclusions: 1) interregional transportation contributes more to the development of regional economic than that of the adjoining transportation; and 2) these indices can be used to designate spatial interactional scopes of regional economy, and accordingly to provide powerful and scientific supports for the planning of regional transportation and economy; and 3) the accessibility figure of network nodes shows that transportation of Gansu Province takes on a phenomenon of high cluster and spatial autocorrelation; and 4) ENDI can also be used to create spatial weight matrix of spatial progress. As calculation of these indices is laborious, several efficient computational methods are developed.