Strategic Plan of the Texas Department of Transportation for Implementing NCHRP 1-37A Pavement Design Guide (05-1353)**
Thomas John Freeman, Texas A&M Transportation Institute
Jacob Uzan, Technion - Israel Institute of Technology
Gregory Scott Cleveland, HDR Engineering, Inc.

The NCHRP 2002 Guide has recently been released for research purposes. It was used in this study to develop a strategic plan for its implementation for the Texas Department of Transportation (TxDOT) operations. The paper focuses on the design of new flexible pavements. The new guide includes all possible variables that may affect the pavement performance. A general sensitivity study of these variables was conducted using an early version of the software. A few focused studies are presented, including: (1) preliminary local calibration of the guide using 11 SHRP GPS sections in Texas; (2) traffic composition effect compared to that of the traditional 80 kN ESALs and of the design load, and (3) effect of the choice of the whether station and of changing the water table depth on performance of the pavement. The results indicate that: (1) the use of the 80 kN ESALs leads to under-designing the structure; (2) the design load concept can be used in screening runs to determine a preliminary design and (3) in the case analyzed, changing the depth of the water table resulted in changing the moduli of the unbound material, but did not affect the performance. Finally, a strategy for implementation was recommended to TxDOT, including (1) training; (2) laboratory testing and equipment acquisition; (3) field forensic studies for calibration; (4) calibration and validation of the guide and (5) additional studies.