URBAN FREIGHT TRANSPORT IN SENSITIVE URBAN AREAS:THE CASE OF PARMA

The paper focuses on the efficiency of one-to-many distribution processes in urban environment. An in-depth 8-month survey of truck activity records from a public Urban Distribution Centre (UDC) located in the outskirt of the city of Parma, has been performed, merging information between a GPS-based databank and a wider operations databank. Tours have been classified according to UDC-customer mutual distances to prove that the efficiency of the distribution process has a clear correlation with the size (and the network characteristics) of the area to serve; when such an area corresponds to the city centre, tours seem to be affected by endogenous and exogenous constraints, which prevent operators from optimizing aspects such as occupancy rate and routes. All of the above led to analytically model trip chain structure using continuous approximations and assess how the multiplicative impact of temporal binding constraints, such as tour length and favourite time slots for deliveries, along with travel time variability due to congestion, can affect the distribution process efficiency