Complexity Of Public Transport Network In Tianjin

With the development of science technology, people are becoming more and more in-depth understanding the network structure. Recently, complex network has become an important interdisciplinary field, which attracts more and more researchers in physics, biology, mathematics, computer , etc. As an important aspect of the urban passenger transportation infrastructure, traffic plays an important role in the city's economic development and improvement of the citizens'living standards. Meanwhile, the design, planning and implementation of pubic transport network affect people's travel.This paper follows the general pattern of modeling to study Tianjin public transportation systems. The paper started from network topological features of Tianjin urban public transportation and constructed three different models: the traffic-station network, traffic line network and public-transit network, which based on the theory of complex network and real-life network. The paper analyzed Tianjin urban public transportation system by introducing some basic and important topological parameters such as node degree, degree distribution, average shortest path length, clustering coefficient, node betweenness, node weight and edge weight and so on. This paper makes a further study on Tianjin urban public transportation using the analysis software of complex network, and an in-depth analysis of the specific meanings of the topological parameters.Deep investigation of the paper proves that the traffic-station network of Tianjin has the scale-free and random properties, the traffic-line network and public-transit network of Tianjin both has the small-world propertie. A trip in Tianjin on public transportation network, the average shortest path equals 16.2, average path change rate is 2.12 times, and average ride time is 78.7 minutes. These results prove that the time consumption is larger. The paper also concluded that in a trip on public transportation network of Tianjin, the average times from a transfer to another are only 0.88. The transfer between any two traffic lines needs 3 times. The results also demonstrate the accessibility of Tianjin urban public transportation can basically satisfy the needs for citizens to travel, but not convenient. Meanwhile, some transportation lines have the transfer function, and parts of the traffic-station have the central role in Tianjin urban public transportation. People should strengthen main construction on some traffic-stations, such as Haiguangsi, Dongnanjiao, Binjiangdao, Baihuodalou, Chengxiangdonglu, Yanghuoshichang, Guloudong, etc. And some transportation lines, such as 503 Road, 651 Road, sightseeing 1 Road, sightseeing 2 Road, 835 Road, 680 Road and so on, should be designed and optimized.Finally, the paper analyzes the robustness of Tianjin public transportation systems when the nodes and lines appear random failure and hostile attack. Meanwhile, the paper take comprehensive consideration of the importance of transportation lines and traffic-stations in Tianjin urban public transportation. And the paper proposes two kinds of improved and optimization schemes, with great capacity, fast and efficient modern urban transit network for the target. Through such two schemes, its whole efficiency of bus transportation of Tianjin will be improved greatly, which was verified by the traffic network model.