Traffic flow fluctuation analysis based on Beijing taxi GPS data

The processes of urbanization and the expansion of urban scale are growing rapidly in China. Therefore, it is important to determine the influencing factors of the traffic flow. In order to evaluate the impact of internal and external flows, the area inside the Five Ring of Beijing is divided into several square-shaped areas. Each segment is defined as a node, and traffic flows between nodes serve as edges of a network. Then a traffic network is constructed based on above. After that, an empirical analysis of the network is implemented to reveal the dynamic changes of the power law exponent that characterizes the relationship between the mean value and division of traffic flows among nodes, in order to discover the fluctuation of traffic flow. The results show that, when the time interval is small, the internal flow and the external flow have similar effect on the traffic network. With the increase of time interval, the external flow has a greater influence on the network, rather than the internal traffic flow. This paper can help government officials in implementing the regulation of traffic.