The purpose of TCRP Project G-10 was to research soft costs in major public transportation infrastructure projects, with the goal of producing a guide for transportation project sponsors to learn more about these costs and better estimate them in the future. This Guidebook is one of two final products from the project and is intended to summarize how the project’s research can be applied to practice. For more detailed information about Project G-10’s data collection, methodology, and statistical analysis, please refer to the Final Report in Part 2, which follows the Guidebook.