The vehicle routing problem (VRP) is one of the most important combinational optimization problems that has nowadays received much attention because of its real application in industrial and service problems. The VRP involves routing a fleet of vehicles, each of them visiting a set of nodes such that every node is visited by exactly one vehicle only once. So, the objective is to minimize the to...

Abstract Carriers can remarkably reduce transportation costs and emissions when they collaborate, for example through a platform. Such gains, however, have only been investigated relatively small problem instances with low numbers of carriers. We develop auction-based methods large-scale dynamic collaborative pickup delivery problems, combining techniques multi-agent systems combinatorial aucti...

The vehicle routing problem (VRP) in trees is a restriction of the general vehicle routing problem in which the underlying graph is a tree. In this paper, we introduce several NP-complete variants of the problem (e.g., common-source, common-destinations, in-place, flexiblerequests, and bring-it-back), and we present five fast approximation algorithms for these variants. We mainly focus on the 2...