We use a branch-and-cut search to solve the Whizzkids'96 vehicle routing problem, demonstrating that the winning solution in the 1996 competition is in fact optimal. Our algorithmic framework combines the LP-based traveling salesman code of Applegate, Bixby, Chvátal, and Cook, with specialized cutting planes and a distributed search algorithm, permitting the use of a computing network located across Rice, Princeton, AT&T, and Bonn. The 1996 problem instance was developed by E. Aarts and J. K. Lenstra, and the competition was sponsored by the information technology firm CMG and the newspaper De Telegraaf. (Combinatorial Optimization; Vehicle Routing; Integer Programming; Distributed Computing) A wide range of practical problems involve sets of customers that need to be served by vehicles located at a common depot; models that optimize the selection of routes to the customers are referred to as vehicle routing problems. To capture different aspects of routing applications, a variety of models have been studied in the literature, starting with the work of Dantzig and Ramser (1959) .
Applegate et al. REF proposed a branch and cut algorithm for solving this problem.
Solution of a min-max vehicle routing problem
INFORMS Journal on Computing
Computer Science