Sustainability in project portfolios: a scoping literature review for the transport sector

Sustainable transport is one of the strategic goals of public roads administrations. The Norwegian Public Roads Administration is working to develop a sustainable portfolio of projects. Literature on sustainable portfolio management for the infrastructure sector could help in developing strategies for portfolio management and succeed the challenges. The purpose of the paper is to identify existing literature on sustainable portfolio management in the transport sector and identify key findings in the existing literature. A literature review is performed by combining the three main keywords of “portfolio management”, “sustainability” and “infrastructure”. Structured search is performed in scientific databases, such as Google Scholar, Scopus and Web of Science, considering relevant keywords’ synonyms and using string combinations. The study shows that there is scarce relevant literature dealing with the topic of interest, combining all the chosen keywords. Partial combinations of the keywords are investigated. The results provide five key findings on the paper’s topic. First, the existing literature on Portfolio Management focused on sustainability is more on energy, finance, data, or product fields, and is seldom related to infrastructure. Second, the literature focuses more on project portfolio selection than on portfolio management. Third, when the literature focuses on constructions, different sets of criteria are used to identify sustainability. As a result, sustainability does not have a unique definition. Fourth, there is little available literature on tools and methodologies for using a set of criteria to select projects specific to the transport sector. Fifth, there is no unison agreement in the literature on which tools and methodologies to use for Portfolio Management in the infrastructure sector. In conclusion, the paper identifies a gap in Portfolio Management focused on sustainability in the infrastructure sector.