Austroads has published two technical reports drawing together the research underpinning changes made to key components of the Guide to Pavement Technology. The reports detail the technical basis for changes made to Guide to Pavement Technology Part 2: Pavement Structural Design and Guide to Pavement Technology Part 5: Pavement Evaluation and Treatment Design. This webinar, presented by Dr Michael Moffatt and Dr Geoff Jameson, outlines the technical basis of the changes made to Parts 2 and 5 since the last versions of the technical basis reports were published in 2008. The 2017 edition of Part 2 included improvements to the design of flexible pavements, significant revision to the procedures used to calculate the design traffic, new procedures for the design of pavements with lime-stabilised subgrades and improved methods to predict the in-service fatigue life of cemented materials and estimate asphalt and cemented material design moduli. The Guide to Pavement Technology Part 5 provides guidance on the selection and design of strengthening treatments to rehabilitate pavements. This is an integral part of managing a road network. The most recent edition of the guide enhanced the design procedure and expanded its use to a broad range of strengthening treatments, including asphalt overlays, inlays, major patchings and stabilisation of pavement layers and subgrade. The procedure is identical to the mechanistic-empirical procedure for the design of new pavements (detailed in Part 2) with the addition of an initial phase which determines the properties of the materials in the road-bed.