One of the biggest limitations in applying automated condition survey techniques to local roads is the ability to detect and measure edge deterioration. This is a widespread problem on local roads, particularly on rural roads without defined edge kerbs, and local authority engineers have highlighted it as one of the main causes of pavement maintenance expenditure.
The research was commissioned to investigate what adaptations could be made to the survey specification in time for surveys starting in 2005/06. The work was undertaken by TRL Limited. The final project report is available here. Initial study of edge deterioration - TTS on local roads
A literature review and consultation exercise found that there were no currently available methods for detecting and assessing edge deterioration which are either routinely used or sufficiently developed for routine use. Because of this, and because of the short timescale for the implementation of automated surveys on non-principal roads, the project team concluded that it would not be feasible to carry out any major hardware configuration changes. The research then went on to consider what could be detected using existing hardware configurations, and made recommendations about potential techniques.
The results of this research project were incorporated in the SCANNER specification for 2005.
Information about a follow-up project to look at further options for detecting edge deterioration is here.