Research On The Stochasticity Of Urban Link Travel Speed Based On Insufficient Taxi GPS Data

With the development of economy and society,nowadays traffic problems are getting more and more serious.It will affect urban traffic and result in large economic losses.The effective prediction of traffic flow is extremely useful reduce the negative impact caused by traffic problems.This can be achieved by obtaining the law of randomness(distribution and spatio-temporal correlation)of urban link travel speed.However,the analysis of the speed requires sufficient data of link travel speed data.If the data is insufficient,the accuracy of the analysis will be affected,or it's not possible.But we often encounter insufficient data in practical research.Therefore,it is very important and more general to obtain the urban link travel speed law when the data is insufficient.We obtain an urban link travel speed dataset by using map matching and speed estimation methods based on taxi GPS trajectory in this research.We also generate some data to overcome deficiencies in data acquisition by using the generative adversarial nets(GAN).This article mainly contains the following contents:1.Based on OpenStreeMaps data,we obtain the road network data,which contain the road network topology and the length of each link.The exact position of the taxi trajectory points on the road network are determined by using the map matching algorithm.The link speed is estimated by using the points' information.And speed data imputation is applied to the links where no trajectory points are collected.2.Based on the fact that the speed data is insufficient to effectively obtain the randomness law.GAN is used to generated additional 15 days of speed data based on the real travel link speed dataset in this paper.Then the maximum mean discrepancy(MMD)is used to evaluate the quality of the generated data.In addition,the validity of the data was verified from three aspects.This has certain reference significance for dealing with the problem of insufficient data in actual research.3.Finally,based on the real speed data and the generated speed data,the randomness law of the road speed is analyzed.