Optimization of AASHTO DNPS86 Pavement Design Program

A nonlinear optimization program is developed to accept the AASHTO DNPS86 pavement design computer program as a subroutine. This enables the obtaining of the least cost design for flexible and rigid pavements without manual interation. Examples illustrate using the 3 design variables for rigid pavements (reliability, subbase thickness, and performance period of intital pavement), and 4 variables for flexible pavements (the preceding 3 plus an additional layer thickness). Minor program changes permit the star-search routine to include additional design variables, at the cost of added computation time. Parametric curves for minimum-cost designs of rigid and flexible pavements are provided that allow identifying the least cost pavement type before the using the program to obtain final layer thicknesses.