Data Collection

The Long-Term Pavement Performance (LTPP) program monitors more than 2,500 asphalt and portland cement concrete (PCC) pavement test sections throughout the United States and Canada. A total of 934 LTPP test sections contain the common types of pavement in use in the U.S. (general pavement studies [GPS]), and 1,580 other test sections have been specially constructed to study certain engineering factors in pavement design (specific pavement studies [SPS]). At each GPS and SPS site, data on distress, roughness, structural capacity, traffic, and other variables are systematically collected. In addition, work groups of highway engineers periodically visit the sites to get a firsthand look at the pavements and to record their subjective observations.

Selected sites within the GPS and SPS experiments were continuously monitored for temperature and moisture as part of the Seasonal Monitoring Program (SMP) study. For the Dynamic Load Response study, various PCC sections within the SPS-2 project were chosen for a study on pavement response under controlled loading conditions.

Additional information includes:

• GPS Experiments: Descriptions of the GPS experiments.

• SPS Experiments: Descriptions of the SPS experiments.

• Additional Studies: Descriptions of the SMP and the Dynamic Load Response studies.

• Data Collection: Monitoring schedules and contact information for each of LTPP's four regional offices.

• How to Get LTPP Data: The Long-Term Pavement Performance (LTPP) data are provided to the public through the LTPP InfoPave™ Web site or the Standard Data Release by contacting the LTPP Customer Support Service Center at 202–493–3035.

• Materials Reference Library: Information regarding LTPP's materials storage facility.