A Lightweight Continual Learning Method for Traffic Flow Prediction Based on B-Splines

Traffic flow prediction is crucial for efficient urban planning, traffic management, and user navigation. Modern deep learning models have achieved great success in capturing the complex spatio-temporal dependencies in traffic networks. However, due to frequently changing traffic patterns, the performance of deployed models degrades over time, necessitating periodic updates. Full-scale model retraining is computationally expensive, creating a critical conflict between maintaining prediction accuracy and minimizing update overhead. To address this, incremental update or continual learning methods have emerged, but existing approaches are often tightly coupled with specific model architectures and rely on unclear criteria for data selection, thereby causing redundant data selection and lacking interpretability. To overcome these limitations, we propose a lightweight continual learning method based on B-splines. This method identifies the most valuable data for model updates by analyzing the intrinsic geometric and statistical properties of the traffic data itself. Specifically, we fit a B-spline curve to create a smooth representation of the core traffic pattern and then compute the regression leverage score for each data point to quantify its structural importance. This strategy decouples the data evaluation process from the internal mechanisms of the prediction model. Since the selected data points directly reflect key features of the traffic pattern-such as peaks, inflection points, and anomalies-our method is inherently interpretable, allowing users to understand why certain data points are chosen. Extensive experiments on multiple real-world datasets demonstrate that our method maintains a high level of prediction accuracy while significantly reducing the computational cost of model updates, offering an efficient and transparent solution for the maintenance of dynamic traffic systems.