This document overviews the Long Term Pavement Performance (LTPP) program and more specifically, how it gathers and processes data describing the structure, service conditions, and performance of in-service test sections in all 50 States, the District of Columbia, Puerto Rico, and 10 Canadian Provinces. To derive benefit from this data, engineers must analyze it, and LTPP s analysis program does just that. It takes the raw data that is collected from more than 2,400 pavement test sections throughout North America and converts it into usable information.