Reclaimed asphalt pavement (RAP) has received wide application in asphalt pavement construction and maintenance and it has shown cost-effectiveness over virgin hot mix asphalt (HMA). HMA with a high content of reclaimed asphalt (RA) (e.g., 40%) is sometimes used in practice, however, it may have significant adverse effects on the life cycle performance and related costs. In particular, challenges may arise as the life cycle performance of RAP is also affected by local climatic conditions. Thus, it is important to investigate whether it is still economic to use RAP under future local climate, with consideration of life cycle performance. A case study was conducted for various road structures on Interstate 95 (I-95) in New Hampshire (NH), USA for the investigation. The case study utilized dynamic modulus testing results for local virgin HMA and HMA with 40% RA (as major material alternatives) to predict life cycle performance of the selected pavement structures, considering downscaled future climates. Then, a life cycle cost analysis (LCCA) was considered to estimate and compare the life cycle cash flow of the investigated road structures. Responsive maintenance (overlay) and effectiveness were also considered in this study. It was found that using 40% RA in HMA can reduce agency costs by up to approximately 18% under the 2020–2040 predicted climate and NH should consider this practice under predicted future climate to reduce agency costs.