Although the 9-1-1 system has been an unqualified success story for more than 30 years, changes in the public's use of technology, the saturation of the mobile market, and the spread of Voice over Internet Protocol (VoIP) telephony over broadband are contributing to greater expectations that the current system will need to address. Because text, data, images, and video are increasingly common in personal communications and are critical to future transportation safety, the 9-1-1 system will be expected to accommodate highly mobile, dynamic communications modes. The architecture of these communication nodes directly counters the fundamental structure of the current 9-1-1 system. To guide and foster a nation-wide vision of a 9-1-1 system for the 21st century, the U.S. Department of Transportation (USDOT) is taking a lead role in the research and development needed to bring about a more capable Next Generation 9-1-1 (NG9-1-1) system that supports emergency call delivery and a response based system that maximises impact across a diverse stakeholder community. There are, however, a large number of operational, economic, political, and institutional issues that must be addressed and reconciled if the NG9-1-1 system is to be implemented successfully across the nation. Implementing NG9-1-1 will likely be a complicated process, requiring the effective, timely and willing co-operation of an array of stakeholders. To address these issues, the NG9-1-1 Initiative has begun researching and analysing the strategic transition elements and options that could be followed to further the progress and implementation of NG9-1-1. This Preliminary Transition Plan will help frame how the government and industry view the deployment of NG9-1-1 and the key decisions that might need to be made by each level of government and the private sector to make implementation a reality. Potential Deployment Approaches Transition to NG9-1-1 is expected to be evolutionary process, involving technological, economic, and institutional change. In some cases, the path to NG9-1-1 implementation will depend on the underlying infrastructure and state of the Public Safety Answering Point (PSAP) and 9-1-1 Authorities. In other cases, the transition to NG9-1-1 may depend on the ability of originating service networks to deliver NG9-1-1 calls via native internet protocol (IP)-based infrastructure to jurisdictions that are prepared to receive those calls.