Effective communication of transportation-related information to vulnerable populations is a critical need during emergencies. Despite its importance, various factors still hinder the development of comprehensive and effective plans for communicating emergency information to mobility-limited individuals during evacuations and other major emergencies. Such limiting factors include the wide diversity of vulnerable populations, their special needs, existing contact and communication barriers, and lack of resources and mechanisms to locate those populations and assist them during emergencies. This paper illustrates the complexity of communicating with vulnerable populations in emergency evacuations through a critical review of the existing literature and state-of-the-practice information gathered recently from transportation and emergency management agency personnel. First, the paper reviews definitions, characteristics, and size of the vulnerable population. Next, principles of effective communication and the special provisions for communicating with vulnerable populations are presented, along with examples of effective communications and communications barriers. Finally, the paper identifies numerous important emergency evacuation communications topics that were not discussed in the literature and offers recommendations for bridging those gaps. Examples include the limited involvement of experts in emergency evacuation communication, the lack of information about the financial aspects and cost-effectiveness of such communications, the need to establish an information clearinghouse to assist in future evacuations, and the lack of standardization and cataloging of appropriate evacuation messages. The paper is presented as a foundation for developing a framework for effective communications strategies, policies, and practices that focus on vulnerable populations before, during, and after all-hazards emergencies.