DEVELOPMENT OF PERFORMANCE PREDICTION MODELS FOR DRY-NO-FREEZE AND DRY-FREEZE ZONES USING LTPP DATA

The Long Term Pavement Performance (LTPP) program is currently in the eighth year of a twenty year project to monitor and collect pavement data on approximately 800 general pavement studies (GPS) sections across the United States and Canada. This paper focuses on GPS 1 sections (asphalt surfacing on a granular base) located in the Dry-Freeze and Dry-No Freeze zones of the Western United States. Approximately 50 sites were selected from these two zones. Using data collected from the LTPP sites, this paper presents the analyses used to develop pavement performance prediction models. Performance is measured in terms of individual distress types, such as roughness and fatigue cracking. A discussion of the problems inherent in such a process is also included. The authors conclude that although it was possible to recognize performance trends, developing meaningful prediction models is not feasible for GPS sections. It is recommended that future analysis along similar lines focus on specific pavement study (SPS) sections.