Study On The Traffic Impedance Functions Of Mountainous City Based On Big Data

Now the urban traffic congestion problem has become a social problem that the city ordinary travelers and city managers focused on.The development of the city and the city ordinary travel affected by the traffic congestion.?Each traveler is spending more and more time in traffic jams.The traffic impedance function plays an important role in traffic assignment.It mainly consists of the link impedance and the node impedance.In this paper,traffic time is the main reference standard of traffic impedance function.At present,with the development and application of big data in terms of traffic,the GPS data and GIS platform technology provide the data support for the construction of a dynamic traffic impedance function modeIn this paper,The goal is to construct the link impedance and node impedance based on the vehicle GPS data,The study is mainly including the following aspects:(1)Study on GPS data treatment methodIn this paper,the threshold method is used to identify and eliminate the drift data of GPS,Application of the corresponding method to identify and deal with the redundant data of GPS generated when the vehicle is parked.Paving the way for the subsequent application of data.(2)Study on road link impedance based on GPS dataAccording to the shortcoming of the traditional speed-time integral algorithm,Using method of Minimum Squares to improve the speed-time integral algorithm by Chebyshev Polynomial Fitting Model.The length of road and the average speed of vehicles passing through road are obtained,Then the time of vehicles passing through road is obtained,The impedance of the road is verified by an example.(3)Study on road node impedance based on GPS dataAccording to the characteristics of GPS data in the junction,the impedance of the node is divided into two kinds of situations,which passes through the junction or passes through after a stop.And the "virtual path" processing is carried out for each direction of the junction,when the vehicle is running on the "virtual path",The speed is a continuous process of changing.Finally,the weighted average method is used to get the time of traffic flow through each direction of the junction.The impedance of the node is verified by an example.In this paper,We combine the GPS data with the road resistance function to solve theproblems of traditional traffic impedance function model construction,It has a great improvement on its comprehensiveness,real-time and transplantation.The results of this paper can provide the help for the choice of the path,the traffic management department and the guidance of the traffic,and it has a certain value for alleviating the traffic jam.