Guest Editorial: Special Issue on Advances in Vehicle Routing

Abstract

Vehicle routing has been one of the main research areas in transportation science over the last 50 years. The design of good models and efficient solution methods to this problem is becoming increasingly important to practice, and the scientific challenges do not seem to diminish. It is possible that the vehicle routing problem (VRP) research community has never been larger or more active than today. In the community there is a clear trend toward development of richer, more industrially relevant models and corresponding solution methods, enabling both larger and more complex real-world VRPs to be solved. The TRISTAN (Triennial Symposium on Transportation Analysis) conferences have become one of the main gathering points of leading researchers from academia and industry in all areas of transportation science. The first TRISTAN conference was organized in 1991 in Montreal, Canada, whereas the following events took place in Capri, Italy (1994), San Juan, Puerto Rico (1998), San Miguel, Azores Islands (2001), Le Gosier, Guadeloupe (2004), and Phuket, Thailand (2007). TRISTAN VII held at Rica Ishavshotel, Tromso, Norway, June 20–25, 2010 continued the tradition of excellence and friendly scientific exchanges. The organizing committee consisted of Henrik Andersson, NTNU; Michel Bierlaire, EPFL (chair of TRISTAN VI); Marielle Christiansen, NTNU; Geir Hasle, SINTEF (chair); and Arild Hoff and Arne Lokketangen, Molde University College. The committee was very happy to receive a record number of 310 extended abstracts. The format only allowed acceptance of 204 papers that were organized in four tracks and 71 sessions, so the rejection rate became unusually high for this conference series. We believe the large number of good submissions and high rejection rate contributed to a high scientific quality. Without the financial support of our sponsors, TRISTAN VII would not have been as successful. The conference website is still available at http://www.sintef.no/tristan. Vehicle routing has always been an important topic at TRISTAN. As far as we know, there has been at least a few sessions devoted to this theme at each conference. At TRISTAN VII, there were more than 20 sessions and about 60 papers related to some variant of the VRP. We were very happy that Michel Gendreau, the Editor-in-chief, agreed to announce a special issue of Transportation Science, devoted to selected publications on “Advances in Vehicle Routing” with ourselves as guest editors. In the call for papers, we sought not only submissions from participants to TRISTAN VII, but the call was open to the entire international research community. We invited contributions covering all topics in the area, including the full range from new problem formulations and new models, via problem analyses to more effective exact or approximate solution methods. The response was good, with a total of 30 submissions. All contributions were peer reviewed according to the usual, high standards of this journal. Our thanks go to highly qualified and thorough referees that helped us accept seven papers. They greatly contributed to the high quality of the final manuscripts. In our view, the selected papers represent excellent work that spans the variety of leading edge VRP research in a good way. “Approximation Algorithms for Capacitated Location Routing” by Harks, Konig, and Matuschke studies variants of the capacitated location routing problem, an important capacitated VRP generalization with many applications where routing decisions are combined with depot location. The authors have designed an algorithm that improves the best known approximation ratio for the multidepot version. The