Attention Based Spatial-Temporal Graph Convolutional Networks for Traffic Flow Forecasting
Shengnan GuoYoufang LinNing FengChao SongHuaiyu Wan
Proposes an attention-based spatial-temporal graph convolutional network that integrates dynamic spatial-temporal attention mechanisms with graph convolutions to model multi-periodic dependencies and achieve superior traffic flow forecasting on highway networks.
Traffic flow forecasting supports efficient highway management within intelligent transportation systems, yet remains difficult because traffic data exhibit strong nonlinear patterns and dynamic correlations that shift across both locations and time periods. Traditional time-series models and early deep-learning approaches often fail to capture these spatial-temporal dependencies simultaneously, leading to limited accuracy especially over longer prediction horizons.
This paper introduces the Attention-based Spatial-Temporal Graph Convolutional Network (ASTGCN) to address that gap. The model processes traffic data directly on the original sensor graph and explicitly models three temporal scales—recent, daily-periodic, and weekly-periodic—before fusing their outputs.
The approach combines a spatial-temporal attention mechanism with graph convolutions in space and standard convolutions in time. Three parallel components, each built from stacked spatial-temporal blocks, learn dynamic node-to-node and time-to-time influences; the components are then merged through learned per-node weights. Experiments used two real-world highway datasets from the California PeMS system (PeMSD4 with 307 detectors over two months in 2018 and PeMSD8 with 170 detectors over two months in 2016), with traffic aggregated every five minutes and missing values imputed by linear interpolation.
On both datasets ASTGCN produced the lowest root-mean-square and mean-absolute errors for one-hour-ahead forecasts, outperforming eight baselines that included ARIMA, LSTM, GRU, STGCN, GLU-STGCN, and GeoMAN. The version without attention (MSTGCN) already surpassed prior state-of-the-art models, and adding attention yielded a further consistent reduction in error. Gains were largest at longer prediction intervals, and the learned attention matrices aligned with actual geographic proximity, providing a degree of interpretability.
These results indicate that explicitly modeling dynamic spatial-temporal correlations can materially improve forecast reliability, supporting more timely congestion management and better use of highway capacity. Because the framework operates on arbitrary graph-structured sensor networks, it can be extended to related tasks such as arrival-time estimation.
The authors note that external influences such as weather or events are not yet incorporated and recommend including them in future work. The current evaluation is limited to two California corridors; broader geographic validation and sensitivity checks on sensor density would increase confidence for operational deployment.
- Paper: Spatio-temporal Graph Convolutional Neural Network: A Deep Learning Framework for Traffic Forecasting, Bing Yu et al. (2017). Reading STGCN first provides the foundational graph-convolutional and temporal modeling framework upon which ASTGCN builds its attention-enhanced architecture.
- Paper: Diffusion Convolutional Recurrent Neural Network: Data-Driven Traffic Forecasting, Yaguang Li et al. (2017). DCRNN establishes the core diffusion-convolution and sequence-to-sequence methodology for spatial-temporal traffic forecasting that directly informs the design of ASTGCN.
- Paper: Graph Attention Networks, Petar Veličković et al. (2018). Understanding Graph Attention Networks is essential for grasping the spatial-temporal attention mechanisms deployed in ASTGCN to dynamically weigh neighborhood correlations.
- Paper: Graph WaveNet for Deep Spatial-Temporal Graph Modeling, Zonghan Wu et al. (2019). Graph WaveNet extends the spatial-temporal modeling concepts of ASTGCN by introducing self-adaptive adjacency matrices and dilated causal convolutions for large traffic networks.
- Paper: Autoformer: Decomposition Transformers with Auto-Correlation for Long-Term Series Forecasting, Haixu Wu et al. (2021). Autoformer builds on the traffic and time-series forecasting foundations established in ASTGCN by introducing specialized decomposition blocks and Auto-Correlation mechanisms.
- Paper: FEDformer: Frequency Enhanced Decomposed Transformer for Long-term Series Forecasting, Tian Zhou et al. (2022). FEDformer continues the long-term forecasting trajectory of ASTGCN by leveraging frequency-domain attention and seasonal-trend decomposition to improve efficiency and accuracy.
