The Benefits of Long-Term Pavement Performance (LTPP) Research to Funders

Tim Martin, Lith Choummanivong
2016 Transportation Research Procedia  
Long-term pavement performance (LTPP) monitoring has been conducted in Australia for over 20 years. This research was funded by Austroads (representing federal, state and territory road agencies, local government and the New Zealand road agency) to promote improved practice and capability for the road agencies. The LTPP monitoring program measured performance by rutting, roughness, cracking and deflection. Initially the program involved a range of designated flexible pavement sites under
more » ... sites under varying conditions of environment and traffic. Many of these LTPP sites were included in the Strategic Highway Research Program (SHRP) of the United States (US). All sites were monitored in accordance with the SHRP protocols. Later long-term pavement performance maintenance (LTPPM) sites were included in the program to: (i) assess the impact of surface maintenance treatments on changes to pavement conditions (works effects, WE); and, (ii) assess the impact of maintenance on road deterioration (RD). A range of RD and WE models were developed using the LTPP/LTPPM observational data in combination with experimental data collected from Australia's Accelerated Loading Facility (ALF) that separately investigated the impact on RD of increased axle load and various typical surface maintenance treatments. The RD models cover the deterministic prediction of functional surface distress (rutting, roughness and cracking) and the loss of traffic load capacity (strength). The WE models cover the deterministic prediction of the impact of a range of typical surface treatments on improved surface conditions. The RD models are currently being used to develop probabilistic distress predictions based on the variability found in the observational data. The future use of probabilistic predictions of RD outcomes will allow road agencies to better quantify the risks involved in managing the pavement infrastructure. Both the RD and WE models are currently being installed in the pavement management systems (PMS) of both state and local government road agencies to provide efficient maintenance allocation and resourcing at a road network level. In the process of developing the RD and WE models, a number of support tools were also developed such as a tool for determining the independent variable representing climate, based on GPS locations, and a tool for estimating deterioration rates from time-series data. The RD and WE models are also being used to estimate the marginal cost of road wear when pavements are subject to increased axle load to increase road freight efficiency. A dedicated research program generally involves a long-term evolutionary process, however, when it is clearly focused on achieving measurable and practical outcomes, such as improving the practices and capabilities of road agencies, the benefits can be clearly defined and quantified when bench-marked against current and past practices. The LTPP/LTPPM research program is annually reviewed and assessed to ensure that the sites that no longer yield useful data are replaced by sites that provide new observational data with respect to environment, traffic and pavement material conditions. of observational and experimental data; road deterioration and works effect model development; sealed and unsealed road performance
doi:10.1016/j.trpro.2016.05.311 fatcat:krtdwxwcujc7xhgo7unrvrknm4