In this paper we propose a hybrid approach for solving vehicle routing problems. The main idea is to combine an Ant System (AS) with a problem specific constructive heuristic, namely the well known Savings algorithm. This differs from previous approaches, where the subordinate heuristic was the Nearest Neighbor algorithm initially proposed for the TSP. We compare our approach with some other classic, powerful meta-heuristics and show that our results are competitive. / Series: Report Series SFB "Adaptive Information Systems and Modelling in Economics and Management Science"

In this paper we present and analyze the application of an Ant System to the Vehicle Routing Problem with Backhauls and Time Windows (VRPBTW). At the core of the algorithm we use an Insertion procedure to construct solutions. We provide results on the learning and runtime behavior of the algorithm as well as a comparison with a custom made heuristic for the problem. / Series: Report Series SFB "Adaptive Information Systems and Modelling in Economics and Management Science"