Assessment of environmentally sustainable pavement maintenance practices

Pavement maintenance (PM) introduces new environmental impacts because of the huge amount of resource consumption, depletion of natural resources, waste generation, and energy consumption, as a result, sustainability issues become a worldwide forefront agenda of transportation agencies (Khahro et al., 2021). Addis Ababa is experiencing rapid population growth and urbanization, necessitating extensive infrastructure development, particularly in road networks. However, the city faces challenges such as traffic congestion, inadequate maintenance, and pavement deterioration, alongside environmental issues like pollution and resource depletion. The main objective of this research was to assess the practice of environmentally sustainable pavement maintenance projects at Addis Ababa city road networks. The PSIM Rating framework is used as the main tool to assess the extent of sustainability across the projects. With indicators being the basis, categories incorporated in the assessment include material usage, maintenance techniques, management practices, energy and water consumption, and environmental impact. Data was collected via in-depth interviews with 8 stakeholders and field surveys across 6 project sites, integrating quantitative data with qualitative interpretations for a comprehensive evaluation. Using AACRA's Lot 1 and Lot 2 pavement maintenance projects as case studies, the research revealed significant variations in approach and outcomes associated with realizing environmental sustainability. Project Lot 1 generally performed better in terms of material usage and waste management, partially incorporating recycled materials and reusing construction waste, highlighting a disparity in resource efficiency. Lot 2 excelled in work zone management and safety measures, effectively reducing disruptions and enhancing safety during operations. While both projects demonstrate a degree of awareness and implementation of sustainable practices, neither consistently achieves exemplary levels across all evaluated categories. The findings show that adopting a proactive and data-driven approach to maintenance management is crucial for long-term environmental sustainability. It is recommended that AACRA standardizes the use of recycled materials across all projects, potentially reducing virgin material consumption. Furthermore, adopting preventive maintenance strategies could extend pavement life, significantly lowering overall environmental impact.