A Key Path-Based Deep Learning Approach for Urban Traffic Speed Prediction

Abstract

Traffic speed prediction in the urban road network is an important and promising task of intelligent transportation systems. Precise traffic speed prediction can mitigate traffic congestion and improve road network utilization. This task is challenging because of the complexity of the spatiotemporal dependency of traffic data among road network. Existing approaches mainly focus on the whole road network and it may capture much redundant information and lead to high computational cost. In this paper, we propose a Key Path-Based Deep Learning Approach: Path-Based CNN-1D + GRU + CNN-2D (P-CGC), a novel deep learning model for traffic speed prediction. Specifically, we use EST-matching algorithm to match the float car data into the road network. Then we select several key paths and build the model for the loop detectors which are in the same key path. We introduce CNN-1D, GRU to extract the temporal dependency of the data, where CNN-1D is used to fuse the contextual information, and GRU is used to capture the features of the temporal dimension. Then we concatenate the output of all CNN-1D+GRU models and use CNN-2D to capture the spatial dependency of the data. Finally, a fully connected neural network is used to transform features into the prediction. We conduct extensive experiments on Zhangzhou real-world datasets, and the proposed approach achieves a good result.