Whether a small fire in a passenger rail vehicle stays small or grows to encompass the vehicle, and how large the ultimate fire may become, is largely a function of the initiation fire, vehicle interior materials (interior lining / components and contents), vehicle configuration and ventilation. Evaluation of the relative fire hazards represented by different interior lining materials as exposed to various initiation fire scenarios can be costly and time-consuming if full-scale fire tests are utilized. However, small-scale fire tests, such as those that utilize the cone calorimeter apparatus, are less expensive (by far) and numerous tests can be carried out in a given day. Small-scale test data, coupled with initiation fire data and computational modeling, can be used to cost-effectively assess a wide range of scenarios and material combinations for existing and proposed vehicle designs. Under a project supported by the Department of Homeland Security (DHS), a methodology for determining flame spread and fire growth behaviors within rail vehicles based upon small-scale fire tests was developed.