Freight demand models are one of the key components of the transport plans at the strategic, tactical and operative level. Local authorities need to predict future transport requirements both for passengers and freight so as to plan the development of infrastructures and related human resources. The private sector requires models to predict transport service demand in order to evaluate future needs. This applies both to transport service managers, producers of consumer goods and firms using transport services, as well as manufacturers of commercial vehicles. One of the greatest difficulties in analysing freight mobility is the identification of decision-makers involved in the process. In the case of freight, there is no sole decision-maker who chooses trip characteristics, but rather a complex set of decision-makers responsible for production, distribution and marketing who, in turn, operate in different fields as producers, who have an economic function and deal with the production of goods, or as consumers, who are freight consumers and become producers of semi-finished goods, destined for the markets and hence towards end-consumers. In this paper a general multi-step model to simulate urban freight transport is proposed. Then the specification, calibration and validation of the attraction model is reported, performed by means of two different samples and corrected by means of traffic counts. The proposed freight transport models, for a medium-size city, with a disaggregated approach, can be segmented in different steps some of which have been specified and calibrated including quantity attraction and distribution models. For the covering abstract see ITRD E124693.
Samenvatting