A Comprehensive Analysis for Obtaining Consistent HDM-4 Results: Case Study with a Local Council in Australia

Abstract

To manage a road network it is vital to have an Asset Management Plan that is consistent and gains the confidence of users and higher management. Muswellbrook Shire Council in Australia is using the Highway Development and Management (HDM-4) as its Pavement Management System (PMS) which is the basis of the Asset Management Plan. Some inconsistencies were observed earlier between HDM-4 results and field. It is essential getting consistent HDM-4 results. The current paper has tried to rectify treatment intervention levels through several HDM-4 runs, site visits and engineering judgment for obtaining sound results. It is observed that treatment decision matrix and data quality are vital HDM-4 inputs. The new and realistic compound standards with treatment intervention criteria have been proposed for urban and rural roads. As a result, the road network is maintained at 5.6 IRI (International Roughness Index, unit is m/km) with A$2 millions ($2 m) per year using 'minimise cost at target IRI' optimisation objective. It is recommended to verify HDM-4 results at site for consistency as there is a time gap between data collection and obtaining analysis results. This is a useful analysis for the asset managers, engineers and planners for obtaining justifiable asset management plan, works program and long-term strategy. Finally, it is suggested that each road authority should have set optimum maintenance standards and strategies derived using HDM-4 in managing their assets.