In Australia over 80 million tonnes of agricultural (including horticultural) output is moved between farms, storage, processors and to markets each year. These movements are characterised by long supply chains; distances between production, processing and markets are often thousands of kilometres, and rarely less than hundreds. To compete, farmers and producers require efficient transport options, which in turn, relies on uninterrupted transport infrastructure and an optimal mix of rail and heavy vehicles enabled by considered policy. To provide a holistic view of transport logistics costs and benefits due to infrastructure investments and policy changes in agriculture supply chains in Australia, CSIRO developed the Transport Network Strategic Investment Tool (TraNSIT). TraNSIT was identified as the preferred tool to help in unlocking a more efficient agricultural transport system to meet the Australian Government's key objective of the Agricultural Competitiveness White Paper of building the infrastructure of the 21st century. Under this programme of work, TraNSIT was able to provide governments, industry, the farming community and other stakeholders with a baseline of freight transport costs between Australian agricultural value chain enterprises, along with a capacity to identify and evaluate a range of scenarios to minimise transport costs and maximise long-term profitability. The extension of TraNSIT to broader Australian agricultural commodities was conducted with support, input and validation from over 80 organisations, agencies and associations representing the agricultural/horticultural and transport sectors. Aside from the insights used to ensure the model reflected industry logistic systems and processes, these contributors provided data for 222,000 enterprises across the commodities supply chains including farms, processors, storage facilities, saleyards, abattoirs, export depots, supermarkets and distribution centres which were incorporated into TraNSIT. The enterprises represented supply chain distribution points for the commodities modelled which were livestock, diary, grains, cotton, rice, sugar, stockfeed and horticulture. From this data a set of synthetic trips were created so that annual/monthly total tonnage (or head) transported across the road/rail network were representative of past movements. In total there were 332,000 different origin to destination paths created. This paper highlights the application of TraNSIT to 98% of Australia's Agricultural production and the importance of the industry and government support to identify synergistic efficiency gains in transport. It represents the largest logistics data set assembled and transport modelling ever conducted for Australian agriculture.