Learning Improvement Heuristics for Solving Routing Problems
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Abstract (arXiv)
Recent studies in using deep learning to solve routing problems focus on construction heuristics, the solutions of which are still far from optimality. Improvement heuristics have great potential to narrow this gap by iteratively refining a solution. However, classic improvement heuristics are all guided by hand-crafted rules which may limit their performance. In this paper, we propose a deep reinforcement learning framework to learn the improvement heuristics for routing problems. We design a self-attention based deep architecture as the policy network to guide the selection of next solution. We apply our method to two important routing problems, i.e. travelling salesman problem (TSP) and capacitated vehicle routing problem (CVRP). Experiments show that our method outperforms state-of-the-art deep learning based approaches. The learned policies are more effective than the traditional hand-crafted ones, and can be further enhanced by simple diversifying strategies. Moreover, the policies generalize well to different problem sizes, initial solutions and even real-world dataset.
Key facts. Cited by 162 papers in the map (data through 7 Oct 2026). First posted on arXiv 12 Dec 2019.
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Citing papers per year: 2021: 20; 2022: 19; 2023: 31; 2024: 34; 2025: 35; 2026: 23.
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- 2023Neural Combinatorial Optimization with Heavy Decoder: Toward Large Scale Generalizationcited by 140
- 2022DIMES: A Differentiable Meta Solver for Combinatorial Optimization Problemscited by 127
- 2022Sym-NCO: Leveraging Symmetricity for Neural Combinatorial Optimizationcited by 118
- 2021Learning to Iteratively Solve Routing Problems with Dual-Aspect Collaborative Transformercited by 108
- 2021NeuroLKH: Combining Deep Learning Model with Lin-Kernighan-Helsgaun Heuristic for Solving the Traveling Salesman Problemcited by 102
- 2021Efficient Active Search for Combinatorial Optimization Problemscited by 99
- 2021Deep Policy Dynamic Programming for Vehicle Routing Problemscited by 94
- 2021Matrix Encoding Networks for Neural Combinatorial Optimizationcited by 89
- 2021Learning Collaborative Policies to Solve NP-hard Routing Problemscited by 86
- 2022Simulation-guided Beam Search for Neural Combinatorial Optimizationcited by 84
- 2023GLOP: Learning Global Partition and Local Construction for Solving Large-scale Routing Problems in Real-timecited by 82
- 2023Learning to Search Feasible and Infeasible Regions of Routing Problems with Flexible Neural k-Optcited by 81
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- 2026Vision-Assisted Foundation Model for Solving Multi-Task Vehicle Routing Problems9 Jun 2026
- 2026MViewRouter: Internalizing Geometric Equivariance via Multi-view Alternating Attention for Combinatorial Routing31 May 2026
- 2026TriSearch: Learning to Optimize Triangulations via Bistellar Flips28 May 2026
- 2026COAgents: Multi-Agent Framework to Learn and Navigate Routing Problems Search Space20 May 2026
- 2026Learning with Foresight: Enhancing Neural Routing Policy via Multi-Node Lookahead Prediction19 May 2026
- 2026A Unified Knowledge Embedded Reinforcement Learning-based Framework for Generalized Capacitated Vehicle Routing Problems14 May 2026
- 2026FiLMMeD: Feature-wise Linear Modulation for Cross-Problem Multi-Depot Vehicle Routing30 Apr 2026
- 2026Learning to Solve the Quadratic Assignment Problem with Warm-Started MCMC Finetuning22 Apr 2026
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