As part of the development and implementation programme to support the introduction of SCANNER surveys on all local roads in England, this project carried out a detailed investigation of the capabilities of automated road condition survey machines to identify and quantify the condition, deterioration and defects associated with the edge of carriageways and associated kerbs and verges on all types and classes of local road, from principal roads to minor unclassified roads. This project builds on the initial study of edge deterioration carried out by TRL in 2004, details of which are here.
This research was carried out by TRL Ltd. The final project report is here: Edge deterioration on local roads
A consultation and review was carried out. This found that the basic requirements were for a measure which indicates the presence of edge deterioration along a length of road, that could detect potholes and measure how far deterioration extended over the width of the road.
The research carried out a thorough assessment of the measures developed during the intial research, refined and improved the measures and developed and tested an overall Edge Condition Indicator, based on a combination of the parameters.
This project also reviewed the results of the initial project on transverse profile analysis, details of which are available here, refined and improved the methods of analysing the transverse profile and the accuracy and reliability of the derived parameters.
These results have been implemented in the SCANNER User Guide and Specification for 2007.
A further phase of the work investigated the development of more sophisticated methods to identify edge deterioration, classify the different types of edge defect including over riding and potholes at the road edge, classify the various types of edge deterioration, and measure the lateral extent of deterioration across the road. This was based on combining information from colour images with transverse and longitudinal profile information, and would require additional, measurement systems on the survey vehicles. The methods developed show promise and were partially successful, but still require further development and additional investment in survey vehicles.