Hurricanes are low-probability, high-consequence events that pose a challenge for disaster planning and management. In the United States, one of the primary ways of ensuring safety from these storms is evacuation. Changing population demographics, risk evaluations, and sociopolitical priorities necessitate occasional updates and revisions to evacuation maps. What are the political and ethical considerations of these map revisions for municipal officials and emergency management professionals? This paper develops an in-depth policy case study of the June 2013 revision of the NYC Emergency Management (formerly Office of Emergency Management or OEM) hurricane evacuation map after Irene and Sandy. By using interviews, document review, geospatial analysis, and process tracing, the research clarified the political narratives advanced upon the release of the new map. This paper finds the mayoral desire for evacuation flexibility, ethical obligation to vulnerable constituencies, and professionalism of the emergency management community drove this recent innovation in coastal storm emergency management. As the result of a long-term process initiated before the hurricanes, OEM’s incorporation of its historical flood experience and adaptation of federal modeling data to suit local social vulnerability planning could serve as a precedent for other municipalities facing similar, complex hazards at the urban scale.