LATENT STRUCTURE MODELLING FOR TRIP DISTRIBUTION

This paper outlines the first stage of a research project investigating the application of latent structure modelling techniques to the trip distribution stage of conventional traffic modelling. It has the objective of developing practical computer methods for fitting latent structure models to trip distribution data, and to investigate whether these models give a substantially improved fit to observed matrices of zone to zone flows. Discussion centres around the results of applying the latent approach to four different types of model - negative exponential, negative exponential quadratic, power and Tanner models - and the computing time and resource requirements associated with each. The paper concludes with a summary of future prospects and suggestions for application to real (rather than artificial) trip data matrices.