Solid waste collection in urban areas is a central topic for local environmental agencies. The operational problem, the definition of collection routes given the vehicle fleet, can greatly benefit of computerized support already for medium sized town. While the operational constraints can greatly vary, the core problem can be identified as a capacitated arc routing problem on large directed gra...

We study variants of the capacitated vehicle routing problem. In the multiple depot capacitated k-travelling repairmen problem (MD-CkTRP), we have a collection of clients to be served by one vehicle in a fleet of k identical vehicles based at given depots. Each client has a given demand that must be satisfied, and each vehicle can carry a total of at most Q demand before it must resupply at its...

Multi-echelon distribution systems are quite common in supply-chain and logistic systems. They are used by public administrations in their transportation and traffic planning strategies as well as by companies to model their distribution systems. In the literature, most of the studies address issues related to the movement of flows throughout the system from their origins to their final destina...

Precision farming in viticulture raises challenging combinatorial issues such as the Differential Harvest Problem . This problem might appear at first similar to a simple Capacitated Vehicle Routing but it exhibits problem-specific constraints that make this much harder solve and which are discussed article. Our objective was develop efficient exact methods using column generation VRPSolver™ ba...

This paper describes the methodology that we have applied for the solution of an urban waste collection problem in the municipality of Sant Boi de Llobregat, within the metropolitan area of Barcelona (Spain). The basic nature of the considered problem is that of a capacitated arc routing problem, although it has several specific characteristics, mainly derived from traffic regulations. We prese...

The Capacitated Arc Routing Problem (CARP) is useful for modeling urban waste collection or winter gritting, at the operational decision level. Many applications require a tactical version, the periodic CARP (PCARP), in which the trips are planned over a multiperiod horizon, subject to frequency constraints. The paper presents this new and hard theoretical problem, its variants, and a powerful ...

In multi-echelon distribution strategy freight is delivered to customers via intermediate depots. Rather than using direct shipments, this strategy is an increasingly popular one in urban logistics. This is primarily to alleviate the environmental (e.g., energy usage and congestion) and social (e.g., traffic-related air pollution, accidents and noise) consequences of logistics operations. This ...

We propose an algorithmic framework that successfully addresses three vehicle routing problems: the multi-depot VRP, the periodic VRP, and the multi-depot periodic VRP with capacitated vehicles and constrained route duration. The meta-heuristic combines the exploration breadth of population-based evolutionary search, the aggressive improvement capabilities of neighborhood-based meta-heuristics,...