If road agencies are to manage their available road maintenance funding more efficiently, then they must improve their investment strategies and develop their works programs.

If they do so, they will improve the performance and safety of road networks, and at the same time maximise the return on investment and improve the safety of the road users.

A road’s performance is influenced by several factors: • the structural bearing capacity of the pavement • the number of heavy vehicles using the road • climate • surface and drainage conditions. Due to the limited availability of structural data, road agencies are forced to use rutting data as a substitute for structural bearing capacity to identify rehabilitation treatment options.

However, this approach fails to assist in the development of investment strategies to reduce the life-cycle cost of the road asset, nor will it maximise the safety of vulnerable road users. The introduction of the traffic speed deflectomer (TSD) has made it more affordable for many road agencies to collect defects data. The use of TSD has created a knowledge gap on methodology/mechanism as road agencies are yet to identify the best means of utilising and incorporating this structural data at network level investment analysis.

This study’s findings will assist to: • Bridge the knowledge gap in TSD structural data usage in network level investment analysis, through the development of a structural deterioration curve. • Simplify the process to use structural data effectively, and in turn develop optimised investment strategies for road agencies to manage their ageing road assets.