A new travel demand forecasting system, based on microanalytic simulation and dynamic analysis, is discussed. The system consists of two components: a microsimulator of household socioeconomics and demographics and a dynamic model system of household car ownership and mobility. Each component comprises inter-linked models formulated at the household level. Replicated in the socioeconomic and demographic microsimulator are interactions and causal paths that underlie life cycle evolution of individuals and households. Output from the sociodemographic component is then used by the dynamic model system of mobility to predict household car ownership, trip generation, and modal split. The parameters of the model system have been estimated using observations from five waves of the Dutch National Mobility Panel data, covering the period of 4 years from April 1984 through April 1988. Other sources of information, external to the panel data, were also used to estimate key parameters. The availability of the large-scale panel data has been essential for the development of the detailed demographic and mobility model components. The model system is a credible and flexible forecasting tool with which a wide range of future scenarios can be examined to answer a variety of "what if" questions. Issues related to the model structure, data requirements, estimation methods, assumptions, and forecasting performance are summarised.
Abstract