• Proposes OTL-GM, an online transfer learning framework with an MLP-assisted GCN that transfers source-domain features to edge devices and bridges domain gaps via online learning.
• Reduces convergence time by 24.77%–95.32% compared with non-OTL models across four traffic flow datasets.
• Addresses critical practical constraints of intelligent edge devices, including limited computing resources, data sparsity, and external environmental influences.
• Enhances timeliness and reliability of traffic flow prediction, supporting real-time route planning and intelligent transportation management.