A period vehicle routing case study

The period vehicle routing problem is a multilevel problem assembling two classical problems: the assignment problem and the vehicle routing problem. Collection days have to be a signed to each customer and vehicle routes have to be designed for each day of the period (time horizon) so that the total distribution cost is minimised. The interaction between the temporal and spatial aspects turns the problem into one of the most challenging variations of vehicle routing. In this paper, we present the study of a real period vehicle routing system: the collection of recycling paper containers in the City Council of Almada, Portugal. (C) 2002 Elsevier Science B.V. All rights reserved.