This research was commissioned to to develop preliminary definitions for a defects index for use with automated road condition surveys on non-principal roads to be introduced in 2005/06. The objective was to develop one or more appropriate condition indicators based on the current TTS measurements for principal roads and those proposed for other roads from three of the other initial research projects.
The work was undertaken by the Chris Britton Consultancy. The final project report is here TTS Defects Index Preliminary Analysis
The project critically reviewed the existing NRMCS, BVPI (Deflectograph, CVI and TTS) and SRMCS indicators and developed a detailed set of requirements for the proposed new 'Defects Index'. preliminary Defects Index was designed using a flexible framework controlled by sets of weighting factors. It was designed to identify those parts of the network in need of further investigation and to provide a basis for drilling down into the TTS data.
The final report recommended that the proposed thresholds and weighting factors should be reviewed by an appropriate panel of stakeholders and tested by pilot trials on data from the principal road network.
The UK Roads Board set up the SCANNER Defects Index Working Group to review the recommendations of the report, the proposed methodology and the thresholds and weightings.
The pilot trials were carried out by TRL under the supervision of the Defects Index Working Group and are reported here.