GoodTrip—A New Approach for Modelling and Evaluation of Urban Goods Distribution

The GoodTrip model estimates goods flows, urban freight traffic and its impacts. This paper discusses the theory and application of the model, that is based on logistical chains. Liveability and accessibility of urban areas are influenced by freight traffic resulting from logistical choices in the supply chain, like warehouse location, delivery frequencies, vehicle type and routing. To support decision making it is necessary to model these choices and their effects, in current and future situations.

In GoodTrip the logistical chain links activities of consumers, supermarkets, hypermarkets, distribution centers and producers. Based on consumer demand, the GoodTrip model calculates the volume per goods type in m3 in every zone. The goods flows in the logistical chain are determined by the spatial distribution of activities and the market shares of each activity type - consumer, supermarket, hypermarket, distribution centre, etc. This attraction constraint calculation starts with consumers and ends at the producers or at the city borders. A vehicle loading algorithm then assigns the goods flows to vehicles. A shortest route algorithm assigns all tours of each transportation mode to the corresponding infrastructure networks. This results in logistical indicators, vehicle mileage, network loads, emissions and finally energy use of urban freight distribution.

GoodTrip is a tool to evaluate different concepts of freight distribution from both a societal as economical viewpoint, by using geographical, economical and logistical data. This was done in a case study for the City of Groningen The modelling approach is innovative and the first results are promising. Model output discriminates clearly between different alternative freight distribution concepts. The modelling results comply with empirical data and real life experience.