This paper presents the state of the practice of the use of cable barrier systems in the United States. A literature review was conducted to identify the types of cable barrier systems being used. The scope of this review included benefits of using cable barriers, available guidelines, policies or procedures related to barrier placement, and issues related to the maintenance and in-service performance of the cable barriers. A comprehensive survey was conducted to identify experiences, practices, and design and construction standards for the use of cable barrier systems. To improve survey quality, survey participants were people identified as managing the cable barrier systems firsthand. The participants were therefore likely to be most knowledgeable about the design and construction, maintenance, and overall experience of cable barrier usage. Concluding remarks about the state of the practice of cable barriers, along with areas of further research, are presented.