Validity and reliability of a transportation infrastructure sustainable performance framework: A study of transport projects in South Africa

Abstract

Transportation infrastructure contributes to the development of an economy. However, the performance of such infrastructure is hampered if sustainability elements are not considered at the initiation/conception and operation stages of the projects. The study aimed to validate a structure of transportation project sustainability measures to evaluate projects and ensure continual delivery of intended benefits in the long run. Empirical data were collected using a field questionnaire survey developed from the literature review and a preliminary qualitative inquiry. A total of 132 built environment professionals were included based on purposeful and snowball sampling techniques. A model-generating confirmatory factor analysis was undertaken to validate underlying structures of sustainability measures established from a preliminary common factor analysis. The findings validated that a four-factor structure, with eleven variables, could adequately measure transportation infrastructure project sustainability (PS). The CFA structure achieved construct, convergent and discriminant validity, with fewer variables than were theorised and subsequently established in the common factor analysis. The validated four-factor structure is envisaged to be useful to transportation infrastructure project stakeholders in better decision-making on project selection being cognizant of these factors, which are indicative of the worthwhileness of projects. In addition, monitoring of the projects during the operational stage, based on the identified indicators, could be done with the aim of delivering long-term benefits to generations of users.