This chapter proposes a decision support system, STG-Sim, that estimates the number of shopping trip chains as well as the related distances to assess the impacts of the retailing structure on the final part of goods transport chains: that of bringing purchased goods to the end-consumer's location. First, the methodological framework of the shopping trip chain estimation is proposed. It includes a generation model (for both motorized and pedestrian trips), a catchment area distribution model (to relate the shopping locations to the household's ones), and a distance estimation procedure. An application to the deployment of four retailing poles (two new ones and two extension ones) in Lyon, France, is also presented. Finally, practical implications and further developments are presented.