A system of models to forecast the effects of demographic changes on urban shop restocking

• We present a general modelling framework to assess medium/long-term city logistics scenarios.
• It allows forecasting of effects due to demographic changes.
• The models take account of the behaviour of several actors associated with urban freight transport.
• The modelling framework was used to assess the effects on shop restocking due to demographic changes in a medium-size urban area.

End-consumer choices in relation to type of retail outlet impact upon shopping travel frequency and mode, and hence on freight distribution flows for restocking shops. The characteristics of the restocking process, in terms of delivery size, delivery frequency, freight vehicle type and so on, are strictly related to the size of commercial activities to be restocked. Since end-consumer choices depend on end-consumer characteristics, such as age, gender and occupation, which change over time in an urban area, changes in such characteristics impact upon the nature of freight restocking. In city logistics analysis, in order to forecast the future characteristics of freight distribution in an urban area, a system of models is required that allows shopping mobility and freight restocking distribution to be considered in an integrated approach, with shopping demand models that take end-consumer characteristics into account. This paper discusses a number of issues related to the transportation impacts of shopping attitudes on urban freight distribution. It focuses on the factors that mainly influence freight distribution: quantity and choices of retail type (including e-shopping). After an analysis of state-of-the-art shopping mobility demand modelling, a new system of models for simulating shopping choices is presented. The models were obtained by using surveys carried out in Rome where more than 300 families were interviewed. Jointly with urban restocking models, they were used to assess the effects on freight restocking under a future scenario when demographic changes occur in a medium-size urban area. The results indicate that effects of demographic changes on shop restocking flows can be significant. For example, the shifting of middle aged adults into later age could result in an increase in shopping trips to nearby shops, mainly to small and medium-size retail outlets. This could lead to a consequent increase in car-kms. Further, expectation of an increase in e-shopping could reduce consumer trips. However, new measures able to promote consolidation for making home deliveries more efficient should be investigated.