Daily Traffic Flow Forecasting Through a Contextual Convolutional Recurrent Neural Network Modeling Inter- and Intra-Day Traffic Patterns

Abstract

Traffic flow forecasting is an important problem for the successful deployment of intelligent transportation systems, which has been studied for more than two decades. In recent years, deep learning methods are emerging to serve as the benchmark tool for traffic flow forecasting due to its superior prediction performance. However, most studies are based on simple deep learning methods that can not capture inter- and intra-day traffic patterns as well as the correlation between contextual factors like the weather and the traffic flow. In this paper, we propose a novel deep-learning-based method for daily traffic flow forecasting where incorporating contextual factors and traffic flow patterns can be critical. First, a particular convolutional neural network (CNN) is deployed to extract inter- and intra- day traffic flow patterns. Then extracted features are fed into long short-term memory (LSTM) units to learn the intra-day temporal evolution of traffic flow. Finally, contextual information of historical days is integrated to enhance the prediction performance. Through a real-data case study, we show that the proposed approach achieves over 90% prediction accuracy which greatly outperforms existing benchmark methods and its forecasting performance is robust under various scenarios.