The project analyzed data from the Long Term Pavement Performance (LTPP) to assess the influence of structural and site factors on the response and performance of new flexible and rigid pavements. This analysis confirmed current understanding of pavement performance and highlighted the interactions between design and site factors.
Recognizing that the response and performance of flexible and rigid pavements under specific site conditions (e.g., traffic level, climatic conditions, and subgrade type) depends not only on pavement layer thicknesses and material properties but also on other design and construction features (e.g., type and details of subdrainage, base, and shoulders), the effects of these features must be considered in evaluating pavement response and performance. Therefore, there is a need to investigate the effects of these features and determine their contributions to achieving different levels of performance.
The research included a review of literature relevant to the response and performance of new flexible and rigid pavements, review and analysis of data available from the Long Term Pavement Performance (LTPP) studies (including instrumented Specific Pavement Studies' (SPS) test sections in Ohio and North Carolina), and performance of analytical investigations. The data were analyzed to enhance understanding of the effects of the design and construction features on pavement response (as measured by deflection and strain) and performance (as measured by type and extent of distress or smoothness). The analytical investigations were performed to identify relationships between design and construction features, site factors, and performance.
The agency report is available online as NCHRP Web-Only Document 74