Entropy-maximizing methods of transport analysis vis-á-vis a physical system theory modeling framework

The entropy-maximizing method suggested by A.G. Wilson (1970) for the development of the gravity model of transportation systems is examined from the physical system theory point of view. Whereas Wilson´s entropy maximizing approach considers the transportation system in the aggregate as a single entity, in order to develop an expression for the system entropy, the physical system theory modeling framework as well as the systemic entropy-maximizing method discussed invoke the component-to-system construct to formulate the requisite expression for the system entropy. Both the physical system theory method and the systemic entropy-maximizing method are endowed with a property that makes it possible for relevant forms of the system-level model to be developed by hypothesizing suitable relationships among the flow-volume and level-of-service variables of the constituent transport links (viewed as components of the transport system) in a manner that is consistent in the network-theoretic sense as well as commensurate with the system model in the behavioral form. Based on this feature, a systemic interpretation of Wilson´s entropy-maximizing method in the context of a few elementary conceptual configurations of a transport network is used to compare entropy-maximizing methods with systemic methods.