Urban goods movements in a sensitive context: The case of Parma

This paper focuses on the efficiency of one-to-many distribution processes in urban environments. An in-depth 8-month survey of commercial vehicle tours leaving from an Urban Distribution Centre (UDC) located on the outskirts of the city of Parma (Italy), was carried out, merging information from a GPS-based dataset and a wider operation dataset. Tours were classified according to UDC-customer distances in order to prove the clear correlation between the efficiency of the distribution process and the size (and the network characteristics) of the area being served. When such area covers the city center, available data highlighted how vehicle routing is affected by constraints which strongly prevent the optimization of routes and occupancy rate. Through continuous approximation models, the relative impact of the time-dependent parameters of the delivery process, particularly maximum tour travel times and preferred time slots for deliveries, was analyzed along with the effects of traffic congestion on commercial vehicle tours. The resulting scenario analysis allowed to assess a significant increase in the number of tours needed (+34,3%) and the total distance travelled (+9%), to serve a given set of customers in the city center, when travel time variability and tour duration constraint become stricter. © 2014 Elsevier Ltd.