Glass Fiber Reinforced Polymer (GFRP) is emerging as a transformative material in tunnel and underground infrastructure due to its unique combination of durability, safety, and adaptability. Unlike steel, GFRP offers exceptional resistance to corrosion in wet, chemically aggressive, and high-moisture environments, making it ideal for long-term use in subways, utility tunnels, and underground structures. Its non-magnetic and non-conductive nature enhances safety and compatibility with sensitive electrical and communication systems. The lightweight property of GFRP simplifies transportation and installation in confined spaces, accelerating construction timelines while reducing labor costs. Advanced fire-retardant formulations and high strength-to-weight ratios also improve safety and structural reliability. With lower maintenance needs and a longer service life, GFRP supports sustainable, cost-effective solutions for underground infrastructure, aligning with the growing demand for resilient and future-proof civil engineering designs.