DEVELOPING THE SINGLY CONSTRAINED GRAVITY MODEL FOR APPLICATION IN DEVELOPING COUNTRIES

Abstract

This research aims to enhance the accuracy of the singly constrained gravity model by incorporating principles from fluid analogy theory. The method is based on an iterative process to generate and allocate trips in an origin-destination matrix and involves estimating the number of trips produced by and attracted to individual zones. The deterrence function and the attraction factor embedded within the model plays an important role in the relative attractiveness of each zone, while the fluid analogy method is used to allocate trips between zones. The method is applied to replicate the distribution of trip-lengths to work by motorcycle in the case-study city of Surabaya, Indonesia for a base year (1993) and for a horizon year (2003). The computed D-statistic and chi-square values indicate that the performance of the combined fluid-analogy and singly constrained gravity model output is better than the conventional singly constrained gravity model in this context