Analysis of Deterioration Models for Lightly Loaded Thin Seal Flexible Pavements

Abstract

A set of deterioration models is required to manage local government authority (LGA) pavements in a cost-effective manner; yet, most existing deterioration models have been derived for the major highways of the State Road Authority system. LGA pavements are different in terms of pavement life, the effect of the environment, loading, and expectations of performance with respect to riding quality. There is a greater emphasis on sustained light routine maintenance in LGAs. There is a need to develop models that more closely represent LGA pavements so they can be used to forecast the deterioration of the asset and to provide better guidance for rehabilitation planning. Existing pavement deterioration models, such as Highway Development Management-III (HDM-III), were examined for application to the Australian LGA pavement set. In general, such models were too complex for use in LGAs, and they also used roughness as a performance measure. Roughness is not commonly measured in LGA pavement networks. Other studies have shown that HDM-III could overestimate the deterioration of lightly loaded pavements. For this study, data on deterioration of several LGA pavements were collected and analyzed. Visual assessment data on pavement condition were captured in a “snapshot” survey of pavements of different ages. Thus, the data represent an age cross-section sample. Little or no correlation was found between any of the performance indicators and age when the full data sets were used for the analyses. Some correlation was apparent with the averaged data for each age. Even then, some of the trendlines observed indicated a performance with age, contrary to normal expectations. It appears that factors besides age have a significant influence on the behavior of LGA pavement.