AbstractRoad infrastructure is engineered to perform through constant exposure to climatological stressors. Due to climate change in particular, expected rises in the average ambient and extreme temperatures, pavement performance might deviate from what was originally predicted at the design stage. This poses serious risks to the long-term performance of this infrastructure because the capacity of a transportation network to provide an acceptable level of service over the period that it was intended for is also seriously affected. However, identifying where potential risks are greatest and where more involved planning and prioritizing is needed is hampered by the lack of vulnerability assessment methods that appropriately integrate failure pathways and engineering decisions. In this study, a new vulnerability index is proposed—extent of pavement grade reliability loss (EPGRL), which has the capacity to capture both flexible pavement performance and transportation serviceability. The index is based on two assumptions. First, flexible pavement performance is directly related to the inherent rheological properties of the asphalt binder, which can be estimated from the performance binder grade requirements for a locale. Second, the level of service of a road network can be represented by its connectivity, expressed here by a network centrality measure, the betweenness score. Two developing countries, Colombia and India, were selected to analyze the capabilities of the EPGRL. The results obtained indicate the EPGRL captures the available performance capability of pavement infrastructure together with the importance of transportation network elements. Hence, it can be used as a tool to evaluate and quantify the vulnerability of transportation infrastructure to future climate change.