A hybrid car-following behavior prediction framework for snowy weather based on stacking ensemble learning

To improve the accuracy and robustness of vehicle car-following behavior prediction on snowy highways, this paper proposes a hybrid prediction framework based on Stacking ensemble learning. The framework integrates a theoretically driven improved Intelligent Driver Model (IDM) with two state-of-the-art data-driven models-the Prediction-enhanced Intelligent Driver Model (P-IDM) and a Transformer-LSTM hybrid network-within a Stacking ensemble architecture. First, an Icy Condition Enhanced IDM (ICES-IDM) model is developed by introducing a road adhesion coefficient mapping function and a speed perception error coefficient to parameterize the classical IDM for snowy environments. Second, a P-IDM model is constructed by incorporating a self-attention-based preceding vehicle speed prediction module into the classical IDM framework to enhance responsiveness to sudden maneuvers of the leading vehicle. Third, a Transformer-LSTM dual-stream network (TL-Net) is designed to jointly predict car-following acceleration by parallel extraction of temporal attention features and recurrent neural network features. Within the Stacking framework, ICES-IDM and P-IDM serve as physics-driven base learners, TL-Net serves as a data-driven base learner, and XGBoost is adopted as the meta-learner to construct a hybrid acceleration prediction model. The model is trained and validated using naturalistic driving data collected in Norway-comprising a dataset of 311,908 observations that link vehicle measurements with weather, road surface, and lighting conditions, along with a five-month road record dataset from Narvik. Experimental results demonstrate that the proposed model achieves a root mean square error (RMSE) in acceleration prediction under snowy conditions that is approximately 28.1% lower than that of the standalone ICES-IDM model, 9.2% lower than that of the TL-Net model, and 4.2% lower than that of the conventional Stacking-IDM-LSTM framework. The model exhibits excellent generalization capability across varying snow intensity levels, providing theoretical support for vehicle car-following safety warning systems in snowy environments.