This study experimentally and numerically evaluated the fire risks and structural vulnerabilities of tunnel-type noise barriers (hereinafter referred to as hereinafter referred to as soundproof tunnels). In Korea, soundproof tunnels are typically constructed using combustible polymeric materials such as polymethyl methacrylate (PMMA) and polycarbonate (PC) for noise reduction and lightweight design. However, due to their enclosed structural characteristics, concerns have been raised regarding heat and smoke accumulation as well as the rapid spread of fire. In this study, fire scenarios were established by varying structural conditions, including roof opening ratios and the presence or absence of central partitions, and analyzed using the Fire Dynamics Simulator (FDS). The results demonstrated that PMMA exhibited a lower thermal decomposition temperature and a higher heat release rate, indicating a higher level of fire risk, while PC showed superior fire resistance with higher decomposition temperature and delayed ignition properties. PMMA rapidly exceeded the critical thresholds for temperature and radiative heat flux, resulting in complete combustion. Central partitions were found to accelerate smoke spread, whereas side or roof openings facilitated smoke discharge to the exterior, contributing to fire suppression and improving life safety. In conclusion, this study confirmed that the fire risks of soundproof tunnel are jointly influenced by the combustion characteristics of the materials and the structural conditions. The findings are expected to serve as fundamental data for material selection and design standard improvements in future soundproof tunnel fire safety.