Paper ID#: 68

Paper Title: The Use of Composite Indices as Resurfacing Triggers

Primary Author: G. Fawcett

Abstract Text : By applying numeric importance weightings to key performance parameters that reflect the overall condition of a road section, we may develop a composite condition index. A composite condition index can be used to monitor and report pavement health or to trigger maintenance actions during both short and long-term programming. A single composite index can replace multiple condition parameters to simplify pavement modeling and treatment selection logic. This paper describes the process of deriving two composite indices, a comparison against multiple condition algorithm treatment selections, and the success rate of applying composite indices for maintenance planning.Historically New Zealand (NZ) has utilized measured surface distresses and a rational treatment selection algorithm for programming resurfacing treatments over a 2-year horizon. More recently, through a national initiative, the dTIMS (Deighton’s Total Infrastructure Management System) software has been implemented for medium to long-term performance prediction and maintenance planning.This report looks at the derivation of a composite Resurfacing Demand Index (RDI) that reflects NZ’s treatment selection logic, and reviews the use of this index as a resurfacing trigger and for reporting network surface integrity. A second, more robust, Surface Integrity Index (SII) was developed during the NZ dTIMS implementation to trigger future resurfacing treatments. The index is composed from surface distresses used by the Highway Development and Management (HDM) predictive models.Both indices include cracking, raveling, potholing and flushing as their main components. RDI also incorporated pothole patching whereas SII included an age and life expectancy component.