Abstract: Binder compositions comprising a bituminous binder and a rheology modifier are disclosed. The rheology modifier comprises a blend of a polyol ester and a C8-C24 free fatty acid component. Asphalt compositions comprising the modified binder compositions are also disclosed. The rheology modifiers help to improve the high-temperature properties of bituminous binders without sacrificing low-temperature performance. The modified binders and asphalt compositions expand the utility of reclaimed asphalt, including reclaimed asphalt shingles and reclaimed asphalt pavement, thereby helping the road construction industry reduce its reliance on virgin, non-renewable materials.