Modeling life-cycle social assessment in sustainable pavement management at project level

Currently, modeling of social impacts in sustainable pavement management (SPM) is still in the infant stage, which generally causes significant social impacts and triggers several social hotspot issues. Therefore, this paper aims to evaluate the social impacts on pavement over its main life-cycle stages.

To achieve this goal, the UNEP/SETAC guidelines were employed to develop the social life-cycle assessment (S-LCA) framework for pavement. Stakeholders, subcategories, and part of social indicators were identified from previous studies, and the other part of social indicators were particularly developed based on pavement characteristics. In particular, direct and indirect social indicators were both used, which evaluate social impacts directly and indirectly, respectively. Moreover, site-specific data were extensively collected and verified using cross-checking by multiple data collection approaches and sources, while generic data were adopted as reference values. Subsequently, the existing approaches of assigning scores were applied for direct and indirect social indicators, and the weights were determined using the analytic hierarchy process method. A final score was aggregated to evaluate the social impacts of pavement. In addition, a case study of traditional hot-mix asphalt (HMA) in China was applied and the social hotspots were identified for the local pavement sector.

This study involved four pavement life-cycle stages of raw materials and production, construction, use, and maintenance, along with 4 stakeholders, 12 subcategories, and 16 social indicators. In particular, the use stage was addressed due to its significant social impacts during the long service life for pavement. Moreover, the subcategories and social indicators associated with worker category were most integrated, and the consumer was incorporated. In the case study of HMA pavement, the use stage contributed the greatest positive social impacts, while local community was identified as an important stakeholder, followed by worker. In addition, the subcategories of health and safety received the top three scores. However, gender discrimination was a significant social problem in the local pavement sector as indicated by the lowest score of equal opportunities subcategory.

The proposed S-LCA framework is effective in evaluating the social impacts of pavement related to affected stakeholders during its main life-cycle stages. This study lays the foundation for the development of S-LCA framework for pavement, and the identified and proposed social indicators not only are used to evaluate the comprehensive social impacts of pavement, but also are suitable for other construction projects.