Graph-Conditioned Mixture of Graph Neural Network Experts for Traffic Forecasting
图条件化的图神经网络专家混合模型用于交通预测
Amirhossein Ghaffari, Saeid Sheikhi, Ekaterina Gilman
AI总结 提出GC-MoE框架,通过图拓扑和近期交通输入为每个节点分配个性化专家组合,仅训练轻量路由模块,在四个基准上提升MAE。
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- An accepted paper at the 27th IEEE International Conference on Mobile Data Management (MDM 2026)
传感器图上的时空预测通常采用统一应用于所有节点的单一骨干架构,尽管图区域可能表现出不同的动态。道路段在功能类别、结构和交通行为上存在差异,表明节点级专家专业化可能是有用的。我们提出GC-MoE,一种图条件化的专家混合框架,基于图拓扑和近期交通输入窗口为每个节点分配个性化的冻结预测专家组合。GC-MoE将冻结的预训练时空GNN专家与输入感知、空间上下文化的路由器相结合,同时仅训练轻量级路由模块。我们还研究了一个有界图条件化输出精炼层作为可选扩展,并仅作为消融诊断包含节点自适应ST-LoRA适配器。在四个标准基准(PEMS04、PEMS07、METR-LA和PEMS-BAY)上,GC-MoE在零参数集成基线上改善了MAE,具有竞争力的RMSE和MAPE,同时在1.5M冻结专家权重之上仅训练约17K参数。实现代码见https://github.com/Ahghaffari/gc_moe。
Spatio-temporal forecasting on sensor graphs is commonly tackled with a single backbone architecture applied uniformly across all nodes, although graph regions can exhibit different dynamics. Road segments differ in functional class, structure, and traffic behavior, suggesting that node-wise expert specialization can be useful. We propose GC-MoE, a graph-conditioned mixture of experts framework that assigns each node a personalized combination of frozen forecasting experts based on graph topology and the recent traffic input window. GC-MoE combines frozen pretrained spatio-temporal GNN experts with an input-aware, spatially contextualized router while training only a lightweight routing module. We also study a bounded graph-conditioned output refinement layer as an optional extension and include node-adaptive ST-LoRA adapters only as an ablation diagnostic. Across four standard benchmarks (PEMS04, PEMS07, METR-LA, and PEMS-BAY), GC-MoE improves MAE over a zero-parameter ensemble baseline, with competitive RMSE and MAPE, while training only ~17K parameters on top of 1.5M frozen expert weights. The implementation is available at https://github.com/Ahghaffari/gc_moe.