A road's performance is influenced by several factors. Owing to the limited availability of structural data, road agencies are forced to use rutting and fatigue cracking 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 traffic speed deflectometer (TSD) has made it more affordable for many road agencies to collect deflection 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 these structural data at network-level analysis. The structural deterioration model is a critical input in the pavement management system for predicting pavement rehabilitation needs. A practically implementable concept was adopted in this study to develop the models. These deterioration models were developed by utilising five years' time series TSD deflection data as a function of other readily available data. This study successfully established structural deterioration models that will enable road agencies to incorporate available TSD data in the pavement management system for developing investment strategies.