Established as part of the Strategic Highway Research Program (SHRP) and now managed by the Federal Highway Administration (FHWA), the Long Term Pavement Performance (LTPP) program faces a significant challenge. Over the past decade, the LTPP program has developed a solid knowledge base for understanding how pavements perform. Its challenge throughout its second decade is to build on this foundation--to further the understanding of why pavements perform as they do. To address this challenge, FHWA has initiated several efforts that require the support and active participation of the States and Provinces. The intent of this document is to describe the challenge the LTPP program faces and explain the efforts underway to address this challenge. This document is presented in the following sections: Introduction; The Challenge; Addressing the Challenge; Critical Issues; and Future Opportunities.