TRB’s National Cooperative Highway Research Program (NCHRP) Innovations Deserving Exploratory Analysis (IDEA) Report 173: Graphene Nanoplatelet (GNP) Reinforced Asphalt Mixtures: A Novel Multifunctional Pavement Material investigates the mechanical and compaction properties of GNP reinforced asphalt binders and mixtures. GNP binders and mixtures are regarded as a potential candidate for the new generation of multi-functional asphalt pavement materials. The report summarizes the current knowledge of the application of nanotechnology to asphalt materials. It also provides an overview of some basic features of GNP materials with their applications to civil engineering, which motivate the investigation of their potential application to pavement materials. The report presents a series of experiments evaluating the mechanical properties of GNP reinforced asphalt binders and mixtures that include a detailed method for material preparation and a quantitative analysis of the effect of GNP on the mechanical properties of asphalt binders and mixtures.