The NYSDOT's Comprehensive Pavement Design Manual (CPDM) was initially used to obtain pavement design solutions.

State-wide average traffic volume parameters and axle load spectra were used to define the traffic. The runs were performed for a road classified as Principal Arterial Interstate, the 90% design reliability level and 15 years design period. The AASHTOWare software was used to run design cases for combinations of traffic volume and subgrade soil stiffness (Mr) for twenty-four locations in New York State. The calibration improved the prediction accuracy for the rutting, fatigue cracking and smoothness prediction models. The thermal cracking model was not calibrated because of erroneous measured data. The local bias was assessed for all distresses models except for the longitudinal cracking model it was found the bias existed for this model even after calibration. First, the AASHTOWare Pavement ME 2.1 with global calibration factors was used to compare the predicted and measured distresses, values that were used for model calibration. Design, performance and traffic data collected on Long Term Pavement Performance (LTPP) sites in the NE region of the United States were used to calibrate the distress models. The work conducted in this research included the local calibration of the distress models for the North East (NE) region of the United States. Due to the advanced principles and design capabilities of the AASHTOWare program, NYSDOT decided to implement the MEPDG and calibrate the distress models included in the software for the conditions in the state. The MEPDG models have been incorporated in the AASHTOWare Pavement ME 2.1 software program that can be purchased from AASHTO. A newer pavement design method, called the Mechanistic-Empirical Pavement Design Guide (MEPDG) was developed by the National Cooperative Highway Research Program to provide a more efficient and accurate design method and based on sound engineering principles. The AASHTO 1993 Guide is based on the empirical relationships developed for the data collected in the AASHO Road Test in the early 1960's. New York State Department of Transportation (NYSDOT) has used the AASHTO 1993 Design Guide for the design of new flexible pavement structures for more than three decades.

Flexible pavement design aashto