Analysis On The Reliablity Of Chengdu Taxi Folating Car Date

With the development of economic, urban road crowd, traffic congestion and environmental pollution problems are more and more serious and the contradiction between the supply and demand of urban traffic is much more critical. Dynamic traffic guidance is a key technology to traffic management and control, however, it is based on the mass, accurate and real-time traffic information. So floating car technology, with a wide range of cover and little factors from weather, is concerned and developed widely.The essence of floating car technology is that GPS data sent by floating car are used to calculate the parameter of traffic state acted by all vehicles in the specific road and the road net by a series of processing. However, in reality, there are a lot of errors from data collection and processing, and different types of vehicles have different driving characteristics, even in the same section, a single vehicle is different to overall vehicles because of traffic lights, other vehicles, etc. Moreover, the detecting intensity and detecting rate are changing over time. Therefore, it's very necessary to analysis the reliability of the road and road net traffic state calculated by the floating car data.This paper summary the factors of the reliability of Chengdu floating car data through the analysis on the source and following application of data, and analyze them detail. Firstly, through actual investigation, analyze that weather the link travel speed of passenger taxies can stand of the overall vehicles', testing the reliability of algorithm used to calculate the link travel speed by floating vehicles. Then, create taxi route choice model based on the prospect theory, analyze the distribution of the detecting intensity of floating car data with Chengdu taxi operation data, find out the weak time period of detecting intensity. Analyze the five minute when the detecting intensity is the min in the weak time period; use Matlab to fit the curve about the different floating car size and the different detecting rate, find out the reasonable floating car number of Chengdu; do the similarity judgment between the traffic parameters of reasonable size and the actual size to test the correctness of the reasonable size. At last, through the investigation and other studies, test the reliability link travel speed and congestion index of real-time traffic information form Chengdu floating system.