GPS provides consistently accurate positioning solutions if four or more GPS satellites can be observed. Unfortunately, this condition is usually not satisfied. ABS (Antilock Brake System) Navigation System consists of self-contained optical encoders mounted on a vehicle wheels that can continuously provide accurate short-term positioning solutions. In this paper, a new concept regarding GPS/ABS integration, based on intelligent method is presented. A fuzzy system is used to identify GPS position accuracy based on environment and vehicle dynamic knowledge. The GPS is used as reference during the time it is in a good condition and replaced by ABS positioning system when...