The objective of this project is to develop a primer for using generative AI models in transportation planning. The primer will advance the knowledge and understanding of the use of generative AI models in transportation planning. The primer, at a minimum, shall: Define generative AI; Describe potential uses, benefits, opportunities, and limitations; Identify the types of data and data quality requirements needed; Identify and prioritize the areas of transportation planning in which generative AI may have a greater impact; Provide a basis for generative AI model verification and validation; Identify risks and challenges, including, but not limited to, biases, equity and ethical considerations, interpretability, implementation, climate and sustainability, and transferability and scalability within and across DOT divisions; Provide recommendations for mitigating the identified risks and challenges; Suggest strategies for workforce development, governance, and change management; and Propose a practical methodology to evaluate the impact of the primer.