Measuring progress towards transport sustainability through indicators: Analysis and metrics of the main indicator initiatives

Abstract Transport is widely considered as a sector with significant positive and negative externalities affecting society, environment and economy. The fact of incorporating the main principles of sustainable development into transport planning is of prime importance. However, moving towards transport sustainability is a challenging task; it requires a paradigm shift as well as the constant monitoring and intensive evaluation of the current conditions through broadly accepted methodological tools such as indicators. In this context, the scope of the current research is to provide a complete picture of the approaches which aim at measuring progress towards transport sustainability as well as facilitating the development of new initiatives by highlighting the major trends. Consequently, a considerable number (78) of sustainable transport indicator initiatives were selected through an extensive literature review. Accordingly, descriptive statistics was used regarding the main features of the examined initiatives, while an analysis focused on the 2644 included indicators was subsequently implemented. The current research illustrates the linkages among the sustainability pillars and the selected objectives/themes. It also points out the great variability regarding the hierarchical structure, categorizes the considerable number of themes found in the literature into smaller groups, presents the most commonly used themes and indicators, and finally proposes an alternative categorization of weighting schemes concerning indexes. An attempt has been made so that this study can become a meaningful operational tool for researchers aiming at promoting the relevant research by contributing to the selection of the most suitable yet compatible and scientifically valid methods for each case.