This document is the sixth volume in the series of seven volumes of HDM-4 documentation. It gives a detailed description of the road deterioration and works effects (RDWE) models currently in HDM-4 and provides some background to their development, particularly from HDM-III to HDM-4. Also included are possible enhancements to some of the models currently in HDM-4. In addition, other deterioration models are presented in this document for consideration in future versions.

The general concepts and approaches historically used in modelling RDWE in HDM are discussed in Part A. The RDWE models for bituminous, concrete, block and unsealed pavements are then presented in Parts B, C, D and E respectively. Part F provides a series of references.