Calibrating the Naples land-use and transport model

The calibration of a land-use and transport model of the Naples metropolitan area in Italy is described. The model is based on the MEPLAN general spatial interaction modelling framework that has arisen from initial efforts at The Martin Centre for Architectural and Urban Studies, University of Cambridge. A variety of parameter estimation methods were employed in the calibration effort. This included use of a process for identifying efficient parameter estimates in nested logit models, automated search routines for identifying values for the coefficients in multidimensional allocation formulae, cluster analysis procedures for developing zoning systems and category definitions, and various forms of log-linear multiple regression techniques. A complex manual procedure was developed whereby this set of methods was applied in a series of successive iterations. These iterations were designed to close in systematically on a model form and set of parameter values that would reproduce observed data that concerned the spatial distribution of different categories of employment and household, various economic interactions between these categories, and trips by person and vehicle on the transport network. The results demonstrate that the process can be used to slowly but surely establish an accurate model fit. This drawing together and practical application of the results of several areas of research has provided valuable experience and insight applicable to future such efforts.