The Development of an Urban Goods and Services Model (UGSM) for London: Modelling Framework and Initial Results
K Arunotayanun, A Sivakumar, J W Polak, Imperial College London, UK
Developed from demand-driven, commodity-based, supply-chain-activity-based and multi-agent-based perspectives, a conceptual and modelling framework of urban goods and service flows is presented with the empirical application for Greater London.
The Urban Energy Systems (UES) project has been undertaken with an aim to identify the benefits of a systematic, integrated approach to the design and operation of urban energy systems, with a view to at least halving the energy intensity of cities. Toward this aim, the project has developed an agent-based micro-simulation tool kit (SynCity) as an integrated platform for modelling urban energy systems. SynCity is a unique urban systems modelling tool in that it models both the demand for resources in the urban area as well as the provision, or the supply networks.
As part of the UES project, the objective of this study is to develop a tool for modelling urban goods and service flows that focuses not only on supply and demand vectors of freight deliveries and services, but also individual and organisational activities involved within the supply chains. The model must be able to estimate business and residential energy consumptions for the supply chain activities, together with understanding and optimising the energy use in cities based on the analysis of the effects of various policy scenarios. In this paper, the preliminary empirical application of the urban goods and services model for Greater London is presented.
The paper begins with a brief overview of the existing urban freight demand modelling literature, focusing in particular on the energy use in freight transport. The review points out a lack of theoretical, analytical and empirical approaches for effectively assessing behavioural responses of either freight agents or individual consumers in current urban freight transport systems embraced with the supply chain concepts. This is followed by a presentation of several alternative approaches to accommodate supply chain agents' behaviours, taking into account the aspects such as negotiation, relationship and interaction. Advantages and disadvantages of each of these approaches are discussed.
The paper then proposes a detailed conceptual framework of goods and servicing transport model. The framework is developed from commodity-based, supply-chain-activity-based and multi-agent-based perspectives. It is also a micro-level model (i.e. bottom-up model) with a demand-driven approach which, unlike the others, simulates behavioural activities at the personal consumption level. Developed from the supply chain paradigm, the model structure is conceptualised in the form of two inter-related and connected layers: Information and Physical Distribution, where the entities in the physical layer (e.g. ports, vehicles, handling and loading units) are controlled by the information layer (e.g. manufacturers and logistics providers). Regarding the estimation of the energy consumption, the proposed conceptual framework accounts for the energy use patterns related not only to activities between facilities, but also to those within facilities.
Based on this conceptual framework, the paper continues to present a much simplified practical modelling framework, illustrating how datasets from different sources will be used despite the limitations of UK freight and service data at the urban scale. These datasets include, for instance, Living Costs and Food Survey from the Office of National Statistics, London Area Transport Survey from Transport for London and Survey of Company Owned Vans from Department for Transport. Although, each of these datasets can be used to develop a number of standalone sub-models for analysing any specific business and policy scenarios, these sub-models will eventually be integrated into the completed urban goods and services model, capable to capture varied behavioural responses of every single supply chain entity and generate the estimate of the energy consumption of the whole system.
In this first application, the proposed urban goods and services model will be implemented to analyse goods and service movements simultaneously in Greater London. Through the simulation of organisational and individual activities, in which demand are derived from the household expenditure on goods and services, such application will be able to more realistically assess the impacts of changes in freight distribution environment, logistical performance and energy consumption with respect to individual social and economic behaviour in the urban area.
Final section presents overall conclusions and highlights future research directions.
Association for European Transport