STUDY OF LTPP PAVEMENT TEMPERATURES

This study focuses on the quality of the pavement temperature data in the Long-Term Pavement Performance (LTPP) program. Reliable pavement temperature data are necessary in the research planned for the LTPP program. Pavement surface temperature measurements and in-depth pavement temperature measurements have been recorded since the beginning of the LTPP program. Until this study, these data have been subject to only broad checks established for individual fields; no additional quality checks were made. The LTPP database is now undergoing various quality investigations focusing on comparisons of the data from two independent sources--infrared surface temperature measurements that were recorded automatically and in-depth temperature measurements that were made manually. The comparative processes identified various data errors and errors in associated data elements such as the time measurement. Examples of such errors include data entry errors such as transposition of numbers and errors in the tens-place entries. Missing data, malfunctioning infrared sensors, and time-recording errors such as errors with time zone changes or daylight savings time changes were identified. All identified pavement temperature errors were submitted for further evaluation, which could lead to either corrections or removal of erroneous data from the LTPP database.