Study on spacing optimization for traffic flow detector

This paper discusses the influence factors of detector spacing optimization. Through the corresponding mathematical conversion, it gets the model parameters which influence the result of detector spacing optimization. IDF (Information Degree Function) is proposed to describe the spatial distribution characteristics of traffic information. Then, this paper gives the calibration method of the model parameters. After a general study on all parameters, this paper proposes the MIVM (Maximal Integrated Value Model). And the SPA (Shortest Path Algorithm) is used to solve the problem. Through the example of the Second Ring Road, in Beijing, the model parameters are calibrated on the field data. According to the result of detector spacing optimization, this paper obtains the reasonable density which is fit for Beijing expressway, and provides the basis for the practical application. The MIVM is fit for other cities, too.