A design methodology for scenario-analysis in urban freight modelling

Urban goods movement modelling is a popular subject in urban logistics research. However, most models remain under-used because practitioners have difficulties to apply them to simulate urban policies and their impacts on transport flows, mainly when the assessed situations are different from the initial usage of the mode. This paper aims to answer to that issue by proposing a methodology of scenario construction and assessment using current models and tools. The methodological contribution of the paper arises on defining the main elements of a policy-based scenario and on developing a procedure to build the inputs a model needs to simulate the impacts of policy-oriented strategies on urban goods transport flows. First, the main elements policy makers can take into account when defining middle term strategies are identified. Then, a scenario construction procedure is proposed, able to build reference scenarios and trend scenarios. An example for the urban area of Lyon is proposed. According to the reference scenario, it becomes possible to compare and understand urban goods movement changes, by implementing the model introducing variations, such as activity relocation or urban distribution centre whose impacts concern not only the freight flows themselves but also the whole urban logistics organisation. In this way, the proposed methodology is adapted to policy-oriented strategic and tactical planning, mainly for public stakeholders.