This synthesis will be of interest to state Department of Transportation (DOT) engineers, legal counsel, researchers, and administrators; transportation product development engineers, equipment manufacturers, and engineering and product manufacturer associations; state, regional, and federal product testing and evaluation centers; and attorneys of law interested in tort liability as it applies to highway innovations. The synthesis describes the current state of the practice for managing product liability to achieve highway innovations. Information for the synthesis was collected by surveying and interviewing state transportation agencies and private transportation related organizations and by conducting a literature search. This report of the Transportation Research Board identifies and discusses specific tort and product liability problems and principles, the specific tort liability experience of public agencies in state DOTs, and the tort liability experience of private organizations involved in introducing new products to the highway market. In addition, details on the litigation risks of highway innovation, the perceptions and perspectives of public agency and private sector personnel, and the state-of-the-art methods to confront litigation risks are presented. Finally, methodological comparisons and a general tort and product liability overview are included in the appendices.