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This report describes the results of a project, carried out in 2000–01, to investigate the enhancements carried out to road deterioration (RD) and works effects (WE) models included in the predictive pavement modelling system, HDM-4, with respect to the HDM-III models used in the NZ dTIMS Setup used now in New Zealand.

The main objective was to recommend the suitability of the HDM-4 RDWE models for the inclusion in the NZ dTIMS Setup. The study also recommended future research requirements for the optimum utilisation of the HDM-4 models for use in New Zealand.

The study was carried out in four stages ie desk study comparison of models, comparison of models using a synthetic dataset, initial calibration of models, and comparison of calibrated models using a real network dataset.

RAMM databases for five different road-controlling authorities (RCAs) were compiled for the required analyses. Synthetic datasets and real network datasets were prepared considering the values relevant to New Zealand conditions. Sensitivity analysis was carried out for calibration factors to identify the most sensitive calibration factors. Special consideration was given to prepare the dataset for initial calibration, with detailed field verification and some additional data collection undertaken. Initial calibration of the HDM-4 models used snap-shot and time-series methods.

The outputs from both NZ dTIMS and HDM-4 were compared using the real network data, and the HDM-4 models were found to include some of the features that are suitable for New Zealand conditions. HDM-4 models were found to be more flexible than the HDM-III models used in the current NZ dTIMS Setup. The potential enhancement of the current NZ dTIMS Setup and further research needs were prepared.

Keywords: HDM-3, HDM-4, NZ dTIMS, calibration, cracking, edge, break, maintenance, modelling, New Zealand, pavements, potholing, RAMM, ravelling, roads, roughness, rutting, strength, texture, traffic