This report documents the study process and key findings that resulted in the Guide to Regional Transportation Planning for Disasters, Emergencies, and Significant Events. The project research included a literature review, survey, interviews and webinars. The Guide's purpose is to help transportation and non-transportation stakeholders, such as emergency managers and first responders, better understand transportation's important role in building resilient communities. The research discovered multijurisdictional transportation planning for disasters, emergencies, and significant events taking place in many locations across the country, in many different institutional frameworks. Such planning shares precepts of communication and collaboration, supported by eight basic principles that enable communities to better recover after a major disruption. Effective planning is comprehensive, cooperative, informative, coordinated, inclusive, exercised, flexible and continuous. By using principles that are shared by multiple sectors, the Guide provides linkages between transportation planning processes, which primarily center on mobility as expressed in infrastructure, equipment and operations, and emergency management planning processes, which aim at mitigation, preparation, response, and recovery. The Guide has an Introduction and four sections: Principles (including characteristics, strategies, and examples); Case Studies from diverse geographic regions and settings; Tools including checklists and discussion guides; and Additional Resources: glossary and annotated list of resources.