This report describes the development of a method for assessing the transverse profile of local roads. This work has been carried in order to assist the DfT in its goal of introducing TRACS Type Surveys (TTS) on the non-Principal Road Network. These surveys are scheduled to begin in April 2005. Existing methods of transverse profile assessment are based on the measured rut depths in the nearside wheelpath. The relevance of such methods in a local road environment is questionable, not least because of the lack of defined wheelpaths on some roads. TRL was therefore commissioned to develop new, more appropriate techniques for assessing the transverse profile of local roads. The timescale for implementation of any new techniques for assessing the transverse profile of local roads was very short, therefore any new methods developed had to be able to provide transverse profile information based on data already available. A method was developed which made use of profile measurements obtained across the full width of the road. The method was tested on a selection of local roads, and it was found that the absolute deviation of the first derivative of the transverse profile was closely related to the rut depth. The method developed was however also able to operate on roads with no clearly defined wheelpath, and also detected non-rutting transverse profile defects. The report describes the method which was developed, and makes recommendations for its implementation, and considers the implications of the work on the wider goal of introducing TTS on local roads. (A)

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