Current road roughness deterioration modelling and analysis tends to focus on the prediction of roughness progression in terms of change in the IRI over time. Since the IRI is simply a summary index of the actual roughness, which simulates the response of a specific type of vehicle (quarter-car), it is difficult to identify the factors that contribute to the deterioration of road roughness. Understanding the factors that lead to the deterioration of roads and identifying the actual mode of road roughness deterioration will help road controlling authorities refine their specifications on road roughness requirements for road design, construction and maintenance to reduce their adverse influence on roughness.
This research project looked at an alternative method to analyse and define the roughness deterioration modes of different pavement sections of the New Zealand road network by analysing the characteristics of the longitudinal profile of the road surface using wavelet analysis.
This characterisation process was used to analyse the effects of pavement type, traffic loading, environment and maintenance regime on the deterioration of road roughness and ultimately should lead to the development of a strategy for maintaining road roughness of different pavement types commonly found in New Zealand road networks.