Aimed at the characteristic of bigger single point location error, a new measuring method using two points relative location measurement to reduce location measurement error was put forward.

Given the observed hydrological data, the model can estimate the posterior probability distribution of each location of change-point by using the Monte Carlo Markov Chain (MCMC) sampling method.

A method for improving the accuracy of vehicle location on road segment is proposed from the theory point of view, and its high accuracy is verified by formula.