Reliability of optimal intervals for pavement strength data collection at the network level

In road asset management, knowledge of current condition and understanding of deterioration rates of pavement strength is essential input parameter for estimating fund allocations for maintenance and rehabilitation work. However, the cost of collecting data on road pavement strength is relatively high. In a previous pilot study, a procedure was developed for optimising longitudinal sampling intervals for collection of pavement strength data for use in network level of road asset management for the State of Queensland, Australia. The findings indicated that pavement strength data could be collected at 1000-meter intervals rather than at 200-meter intervals for a tropical region of northeast Queensland, Australia. This paper presents the results of the continuing research to assess the reliability of the usage of the 1000-metre interval pavement strength data in predicting budget estimates for road maintenance and rehabilitation at the network level. In the reliability assessment, the 95th percentile budget estimates were compared with the budget estimates calculated from 1000-metre interval pavement strength data. The results indicated that the differences between the 95th percentile budget estimates and the budgets estimated from the 1000-metre interval pavement strength data were less than four per cent for 10-,15-, 20- and 25-year budget estimates, and were approximately 12.25 per cent for 5-year periods.