Abstract:

Based on the actual spatio-temporal topology of the traffic network， a Feature Fusion Graph ATtention network （FF-GAT） model was proposed to fuse multiple traffic state information obtained by nodes， so as to predict the highway traffic flow. First， the correlation features among the vehicle speed， traffic flow and occupancy of the nodes were analyzed， and based on the multivariate temporal attention mechanism， the relationships among the vehicle speed， traffic flow and occupancy were incorporated into the attention mechanism to capture the dynamic temporal correlation between different moments of traffic flow. Then， the nodes were divided into different sets of neighborhoods， and the spatial correlation between different neighborhoods of traffic flow was captured by the feature fusion Graph Attention neTwork （GAT）. At the same time， the coupling correlation between multiple heterogeneous data was fully explored by the feature crossover network to provide effective information supplement for predicting the target sequence. Experiments were carried out on two publicly available traffic flow datasets. Experimental results show that FF-GAT model reduces the Root Mean Squared Error （RMSE） by 3.4% compared with ASTGCN （Attention based Spatial-Temporal Graph Convolutional Network） model and 3.1% compared with GCN-GAN （Graph Convolutional Network and Generative Adversarial Network） model on PeMSD8 dataset. It can be seen that FF-GAT model can effectively improve the prediction accuracy through feature fusion.

Key words: highway traffic flow prediction, Graph Attention neTwork (GAT), attention mechanism, feature crossover network, spatio-temporal topology

摘要：

基于交通网络的实际时空拓扑，提出一种特征融合图注意网络（FF-GAT）模型融合节点获取的多种交通状态信息，预测高速公路交通流。首先，分析节点的车速、交通流和占有率之间的关联特征，并基于多变量时间注意力机制，将车速、交通流和占有率之间的关系融入注意力机制，从而捕捉交通流的不同时间之间的动态时间相关性；其次，将节点划分为不同的邻域集，并通过特征融合图注意网络（GAT）捕获交通流的不同邻域之间的空间相关性；同时，通过特征交叉网络充分挖掘多个异构数据之间的耦合相关性，为预测目标序列提供有效的信息补充。在两个公开交通流数据集上的实验结果表明：在PeMSD8数据集上，与ASTGCN（Attention based Spatial-Temporal Graph Convolutional Network）模型相比，FF-GAT模型的均方根误差（RMSE）降低了3.4%；与GCN-GAN（Graph Convolutional Network and Generative Adversarial Network）模型相比，FF-GAT模型的RMSE降低了3.1%。可见，FF-GAT模型能够通过特征融合有效提高预测精度。

关键词: 高速公路交通流预测, 图注意网络, 注意力机制, 特征交叉网络, 时空拓扑