New Zealand started a Long-Term Pavement Performance (LTPP) programme on the state highway network during 2000. This report presents the first concrete outcomes from the calibration analysis, undertaken in 2005.
The cracking model, particularly the crack initiation model, is one of the most crucial in the simulation of pavement deterioration. It contributes to many other pavement models such as roughness and rutting. A comprehensive process of data analysis was carried out including a traditional calibration coefficient adjustment of the HDM-4 model, adjustment of all HDM model coefficients based on maximum likelihood estimation, linear model regression, and logistic model development. The same process was followed for the texture and rut progression model. The simplified model format of the texture model has been calibrated. Reviewing the model format of the rut progression has been less successful due to data shortages but a path for the next stage of development is proposed.
This research from 2005 highlights the merits of the various calibration and model-development techniques as well as providing a comparison of the model outcomes. This is done both in terms of their accuracy in predicting crack occurrence on a network and their applicability to networks outside of the development area.
Keywords: calibration, crack initiation, dTIMS, HDM, LTPP, pavement performance, road deterioration, roughness model, rutting, surface texture