Successful technology commercialization is important for business profitability, and government policies can help or hinder firms' success. As a regulator, government affects standard setting and the nature and scope of property rights. As a sponsor, government can empower technology commercialization by its financial support of new technology. As a first user, government can significantly enhance the chances of successful technology commercialization. And as a buyer, government accounts for a substantial part of the world economy. Previous research on government's roles in technology commercialization mainly addressed the effects of specific roles. However, there is little understanding about the combined impact of these roles on technology commercialization. This article develops a conceptual model to analyze the combined effect of these roles on technology development projects. This model is based on a review of the literature on large technical systems, technological regimes, and technology policy that enabled this study on government's diverse roles in technology commercialization. To refine the conceptual model, an in-depth analysis of three technology development projects was conducted. The empirical findings are drawn from road infrastructure. In that sector, government is the dominant customer and first user of most new technologies. Therefore, government has to create a market for those technologies and strongly affects their viability. This research has produced several major results. First, the developed model is the first to conceptualize the relevant relationships between the various roles of government in technology commercialization. Second, this study has shown that government's behavior as a regulator and sponsor conflicts with its preferences as a buyer and user. Consequently, the support of and demand for new technology is inconsistent and uncoordinated, leaving firms with significant uncertainties in assessing market opportunities. Third, the dominant position of government as a buyer in road infrastructure weakens the effectiveness of intellectual property rights. Fourth, existing studies on technology for partially public goods are mainly historical accounts, and only a few are empirical studies on innovation processes. This study provides an in-depth analysis of the development and commercialization of technology for partially public goods. This article concludes with policy implications and suggestions for future research. An important policy implication is that government could improve technology commercialization by either stimulating the commercialization of various competing technologies or developing various competing products based on the same technology. A central issue for future research is how firms can involve government in its diverse roles in technology commercialization. Most of the existing research on customer involvement deals with consumer and business-to-business markets. A better understanding of government involvement could help firms to overcome the impediments they face in dealing with government.