Reactive polymer technology refers to a class of asphalt modification approaches in which polymer additives chemically react with specific fractions of bitumen rather than interacting solely through physical blending (Figure 1). Unlike conventional elastomeric modifiers such as SBS, reactive polymers—typically epoxy-functional or isocyanate-based—form covalent bonds preferentially with the polar components of bitumen, including asphaltenes. This controlled chemical reaction generates a fine, crosslinked polymeric network within the binder, enhancing its internal structure and performance under traffic loading.