RouteOpt: An Open-Source Modular Exact Solver for Vehicle Routing Problems

Despite significant advancements in exact methods for vehicle routing problems (VRPs) over the past three decades, there remains a lack of high-performing and accessible open-source solvers for researchers and practitioners. To bridge this gap, we introduce RouteOpt, the first open-source modular exact solver for VRPs, delivering state-of-the-art performance while maintaining a flexible and extensible structure. RouteOpt achieves the best performance reported in the literature on both the capacitated vehicle routing problem (CVRP) and the VRP with time windows. Crucially, its modular design allows users to develop and integrate customized branching, cutting-plane, and variable reduction modules to tackle a broad range of VRP variants. Furthermore, RouteOpt introduces a novel node restoration mechanism, enabling efficient parallel processing of a branch-and-bound tree. Leveraging this feature, we have for the first time proven the optimality of three open CVRP instances. By combining modularity, efficiency, and open accessibility, RouteOpt establishes itself as an invaluable platform for both academic research and real-world applications. The source code of RouteOpt and relevant data are publicly available in the RouteOpt repository.

History: Accepted by Ted Ralphs, Area Editor for Software Tools.

Funding: This work was supported by the Division of Civil, Mechanical and Manufacturing Innovation [Grant CMMI-2309667].

Supplemental Material: The software that supports the findings of this study is available within the paper and its Supplemental Information (https://pubsonline.informs.org/doi/suppl/10.1287/ijoc.2025.1415) as well as from the IJOC GitHub software repository (https://github.com/INFORMSJoC/2025.1415). The complete IJOC Software and Data Repository is available at https://informsjoc.github.io/.