A four-level hierarchical framework for reviewing infrastructure sustainability assessment systems

Infrastructure sustainability assessment (ISA) has become increasingly important for achieving sustainable development goals. ISA systems are widely adopted by different stakeholders such as governments, architects, engineers, and academics to assess the manner in which sustainability is incorporated in infrastructure projects. However, a systematic understanding of ISA systems is lacking, and the multifaceted and complicated features of such systems were overlooked in the literature. Thus, this study aims to develop a four-level hierarchical framework (covering the levels of contexts, methods, measures, and results) based on the dialectical system theory, and to use this framework for a comprehensive review of international ISA systems. Fourteen existing ISA systems were reviewed, and six were carefully selected and examined in detail. An enhanced five-pillar concept (i.e. technology, economy, environment, society, and institution) of infrastructure sustainability is proposed to evaluate the measures included in the ISA systems. The results show that dialectics exist within, and encounter challenges at, all four levels of the systems. This study suggests four recommendations to improve the ISA systems: enhancing the balanced concept of sustainability, advancing the promotion of ISA systems, pursuing user-friendliness, and considering the synergies between the assessment components of ISA systems. The developed framework with its dialectical considerations provides a new approach to understanding the complexity and dynamics of ISA and will help raise practitioners' awareness of the dialectical connections in ISA systems and support practitioners’ management practices. In addition, the five-pillar concept of sustainability is beneficial for stakeholders in appraising infrastructure more comprehensively.