A vehicle information system which includes an in-vehicle system and a centralized server system. The in-vehicle system communicates with the server system using a wireless communication link. The vehicle receives a reference signal from a positioning system, computes position data related to the location of the vehicle using the received reference signal, and transmits the position data to the server. The vehicle receives from the server position correction data and determines estimated coordinates of the vehicle, including combining data computed from the received reference signal and the position correction data. Computing the position data and determining the estimated coordinates are performed repeatedly for an interval of time using the same received position correction data, and subsequent to the interval of time, are performed repeatedly without using the received correction data.