Cost Benefit Analysis of Underground and Above Ground Structures

This study presents a comprehensive cost-benefit evaluation of underground and above-ground structures, emphasizing both direct construction costs and long-term socio-economic impacts. Underground structures, including metro tunnels, basements, and underground parking, typically incur 40–60% higher initial costs due to excavation, complex foundations, groundwater management, and structural reinforcement requirements. However, they offer significant benefits such as land conservation, congestion reduction, environmental integration, and enhanced urban resilience. Above-ground structures, in contrast, are more affordable initially, requiring simpler foundations and faster construction timelines, making them suitable for regions with greater land availability and shorter project deadlines. The methodology adopted a mixed approach, integrating literature reviews, cost modeling, lifecycle cost analysis (LCCA), and comparative case studies of urban transportation projects. Results indicate that underground projects, while nearly 1.5–2 times more expensive per kilometer than elevated alternatives, yield higher passenger capacity, improved safety, and better alignment with compact urban development goals. Elevated structures, though cost-effective, face higher exposure-related maintenance costs over their lifecycle. The findings underscore the importance of context-specific decision-making, where underground construction is optimal for dense metropolitan areas, whereas above-ground solutions are more practical for suburban or rural development. This research establishes a balanced framework to guide engineers, urban planners, and policymakers in selecting the most cost-effective and sustainable infrastructure solution while accounting for long-term economic, environmental, and societal benefits.