Abstract
The development of sustainability assessment and sustainability reporting tools (SRTs) for infrastructure is pivotal because they serve to inform on progress towards achieving sustainability goals. However, the assessment of sustainability can be improved. The purpose of this paper is to draw attention to the deficiencies and limitations of existing SRTs and offer an alternative framework that is intended as a guide to enhancing assessment and reporting, and addressing current deficiencies. The alternative framework proposed encompasses six elements: (1) systems-based criteria selection; (2) quantitative measurement scales for criteria; (3) characterizing each criterion by a measure of central tendency and dispersion; (4) the distinction of additionality; (5) criteria weighting; and (6) combining criteria to give an overall score characterized by a measure of central tendency and a measure of dispersion. This is based on infrastructure project comparison. It is contended that, within the alternative framework offered, overall sustainability scores obtained provide an improved characterization of sustainability, because of the acknowledgement of the different elements and their combination. The paper offers a rational way by which the sustainability of infrastructure projects can be gauged and compared