PURPOSE OF MANUAL Th is manual of practice presents information to guide pavement design engineers in making decisions and using AASHTOWare Pavement ME Design for new pavement and rehabilitation design. Th e manual does not provide guidance on developing regional or local calibration factors for predicting pavement distress and smoothness. A separate document@ Guide for the Local Calibration of the Mechanistic-Empirical Design@ provides guidance for determining the local calibration factors for both HMA and PCC pavement types ( 2).