Hidden Social Networks That Drive Online Public Involvement in Infrastructure Construction Case Study of Light Rail Transit Projects in North America

Several studies have emphasized the role of social media in public involvement during planning, construction, and operation of infrastructure. Social media can offer optimal, bidirectional communication with the public and an efficient flow of information and feedback between decision makers and project end users. However, the underlying social networks formed in the background of public relations processes on online social media largely have been neglected. Such networks are referred to as infrastructure discussion networks (IDN) and can be rich sources of information for decision makers. If it can be proved that these networks follow the general behavior of social networks, then rich tools developed in social network analysis can be used to profile users and help decision makers study user attitudes. This paper compares the IDNs of four light rail transit projects in various cities in the United States and Canada and studies them under the microscope of social network analysis. The study shows that IDNs exhibit the general structure of social networks (such as small-world behavior, scale-free degree distribution, and high clustering). The IDNs also include meaningful communities, detection and evaluation of which could lead to more efficient offline and online public involvement processes. Given the recent trends in presence of infrastructure projects on online social media, the methods presented in this paper can be readily applied by practitioners to improve their public engagement practices.