Calculation Method for Aggregate Link Capacity in Aggregated Road Networks

Abstract

This study developed a method that can aggregate the detailed road network of DRM to an arbitrary size and also calculate the aggregated link capacities. The developed method first assigns capacity to each link in the DRM, performs simple aggregation such as unbranched links, and sets the link capacity to be assigned between exogenously given representative node pairs using the route selection probabilities of the logit model. The aggregated link capacity between representative node pairs is then calculated by solving the maximum flow problem. We applied the proposed method to a small area in the Kagoshima metropolitan area and confirmed that the composite capacity differs depending on how link capacity is allocated between representative node pairs, and inferred the cause of this difference. We further applied the proposed model to the entire area of Kagoshima metropolitan network, and then confirmed that the aggregated capacity is fairly independent of the value of the dispersion parameter in the logit model.