The objective of this research, which was carried out between 2010 and 2012, was to investigate the effectiveness of the current road condition rating system with a view to improving the accuracy and confidence in the data collected. This in turn will build confidence in key network performance indicators.
The use of visual road condition rating data in New Zealand has evolved from its original purpose of identifying carriageway sections on a network level for treatment and from being employed in the development of a forward works programme. Visual rating data is now used as an input into a series of performance measures and other pavement/surfacing performance modelling. This research project looked at the how the visual rating process is currently undertaken and whether this is appropriate for its current and future uses. With the move towards using the data to compare road controlling authority networks, confidence and consistency in the data is paramount.
The research recommends improvements to data collection methodology, rater training, quality auditing, survey stratification and sampling methodology and procurement.