In general, tunnels are designed with an abundance of safety regarding structural integrity, however, there can be uncertainty related to structural performance after a fire event. The residual condition of a tunnel after a fire is dependent on fire intensity and duration. The goal of this study is to correlate visual and material characteristics of structural and nonstructural components of tunnels with fire temperature and exposure time. This can be further related to the residual capacity of structural members in a tunnel, providing insight into safety and overall functionality. Experimental results show that the visual response of materials with heat exposure is variable and dependent on a number of factors. A wide range of materials were studied to establish a well-versed collection of data that may be used in a post-fire inspection. In addition, mechanical testing of three configurations of structural slabs exposed to different heating regimens was conducted. The influence of heat on a structural member may be complex, and was found to be minimal for the heating regimens and loading procedures applied. This work can serve as an aid for post-fire investigation by providing methods to estimate fire intensity and duration through visual observation and mechanical testing.