LONG-TERM PAVEMENT PERFORMANCE PROGRAM: REAPING LARGE REWARDS FROM SMALL IMPROVEMENTS

The Long-Term Pavement Performance (LTPP) program is the largest and most comprehensive pavement performance study ever, collecting uniform, comparable data to indicate how variations in maintenance, loads, climatic factors, and subgrade soils affect the performance of asphalt concrete and portland cement concrete pavements. Established in 1987 and initially operated as part of the Strategic Highway Research Program (SHRP), the LTPP program is eminently practical and results-driven. State highway agencies are both owners of the program and customers for its products. They designate the test sites, construct and monitor the test sections, supply test materials, and collect traffic and other data from the test sites. At the midway point in its 20-year life, the program is already yielding products aimed at improving the selection and effectiveness of pavement maintenance strategies, the performance of various pavement rehabilitation techniques and materials, and the design features for new construction or reconstruction of pavements. This article discusses the LTPP program objectives, the LTPP data base and data analysis plan, and LTPP products that are available or under development.