This paper presents a car navigation system for a future integrated transportation system forming a component of an Intelligent Transportation System- ITS. The system focuses on the mechanisms of how to detect the current position of each vehicle and to navigate each vehicle. Individual vehicular data is collected using the Global Positioning System - GPS, for location data and it will then be transmitted to a control center via a mobile phone. For the purpose of this paper, the device will be referred to as “Reporting Equipment for current geographic Position” or REP. It is suspected that if a great number of REP equipped vehicles report their positions to the control center simultaneously, there would be a heavy load on the computational communications network (“network”). This paper proposes an algorithm to reduce the network load associated with large numbers of vehicles reporting their position at the same time; if a car skips some reports then it is not possible for the control center to estimate its correct position therefore we need an algorithm that aims to decrease the frequency of the reporting without sacrificing the proper level of accuracy for the position. Compared to periodical reporting, the load effectiveness shows a 50-66% improvement.