Paper presented at the 32nd Annual Southern African Transport Conference 8-11 July 2013 "Transport and Sustainable Infrastructure", CSIR International Convention Centre, Pretoria, South Africa.
The method to describe pavement condition, as documented in the existing TRH22 document, has specific shortcomings when several defects of slight degree, or when only
major defects e.g. potholes exist on a road segment.
Following the testing of several alternative techniques, a deduct-point method was implemented and calibrated to calculate different condition and need indices in the Pavement Management System of the Western Cape Provincial Government.
This paper describes the background to the deduct-point approach, the processes followed to determine appropriate deduct values for any combination of defect degree and extent, as well as the aggregation of individual deduct values to describe, for example a pavement condition and a reseal need index.