By supporting trading activities urban freight distribution contributes to the dynamism of the cities. But policy makers have now to develop new logistics scheme that can minimize its negative impacts. This paper focuses on the consolidation of goods flows by using a Distribution Center. It appears to be a good solution to meet the new objectives of the policy makers: redesigning the flow of goods inside the city while not increasing the cost, reducing pollution and making the city more attractive. To dimension the DC, we have conducted a survey with the main customers of urban logistics services: retailers and store managers. The results of this survey are now used in order to optimize the delivery rounds in the city.