Abstract
In recent years, besides real-time traffic data, statistical data based on historical traffic data has also been used as a useful compensation to predict the travel time. According to the research on traffic information quality in some big cities of China, it is found that the accuracy is different between real-time and statistical traffic data, and the comparison result depends on the congestion level (smooth, light and heavy congestion).This paper shows these differences and proposes a method to promote the travel time prediction by combining real-time and statistical data according to the congestion level of each road link.