This document provides an overview of the Transportation Infrastructure Model (TIM), which identifies least cost infrastructure options to balance regional gas supply and demand in Indonesia until 2040. The model minimizes transportation costs across pipeline and LNG connections between regions based on inputs from the Detailed Assessment of Supply Scenarios model. Key outputs include optimized interregional flows, infrastructure capacity requirements, unmet demand volumes, and delivered gas costs by region. The document outlines the model assumptions, scenarios, limitations, and how to operate the model by running optimizations and adjusting inputs and connection concepts. It also provides an example of comparing results from base and high demand cases and adjusting connection concepts to find a more optimal infrastructure combination.