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 non-structural 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.