A goal of the Long-Term Pavement Performance (LTPP) program is to provide the data necessary to improve our ability to predict pavement performance. Performance prediction is a critical element in effective pavement design and management; however, it suffers from a lack of accuracy in the models and a high degree of variability in the input data used to drive the predictions. The eventual objective is a set of distress specific performance models that can be used to reliably predict pavement performance related to traffic, the environment, material properties, etc. These models can only be developed using reliable, good-quality pavement distress measurements.