Intelligent Transportation Systems, or ITS, is the application of electronics, communications, and/or information processing to improve the efficiency and/or safety of surface transportation systems. ITS can improve transportation safety, mobility, and societal productivity through the integration of advanced communications technologies into the transportation infrastructure and in vehicles. ITS encompasses a broad range of wireless and wire line communications-based information and electronics technologies. This report documents several case studies of how agencies used work zone intelligent transportation systems (ITS) to mitigate safety and mobility issues in work zones. The report illustrates how to apply a systems engineering-based decision-making process to designing, selecting, and implementing a system to address work zone needs. The report presents the steps followed by the agency/contractor in this decision-making framework for five specific projects. The work zone ITS deployments documented provide examples of selecting and deploying commercial off-the-shelf (COTS) systems; a tailored design and integration of ITS for a specific work zone purpose; and using and supplementing permanent ITS deployments for work zone management purposes. Tips are provided for how to effectively apply ITS to other work zones.