Extending the service life of asphalt pavement and cutting maintenance costs are two reasons self-healing technologies have drawn growing attention. Based on 66 studies published between 2011 and 2026, this review covers four engineered self-healing technologies: induction heating, microwave heating, microcapsule-based healing, and microbial-induced calcium carbonate precipitation (MICP). Quantitative comparisons are made for the first three; microbial healing is discussed separately because only four studies were found. Induction heating has been tested in the field and can reach healing efficiencies of up to 96.5% (maximum reported value). Microcapsule-based healing has a reported peak efficiency that approached 100% under optimal conditions, but can only be used once. Microwave heating heats more evenly across the pavement depth but has not been tested in the field. Microbial healing is at an early stage, with modest strength recovery (UCS, unconfined compressive strength, up to 47%). This review argues that evaluation fragmentation—the use of different indicators, test conditions, and material formulations across studies—makes it difficult to compare technologies and hinders field use. A standardized dual-index evaluation framework is proposed, along with three research priorities: adopting standardized protocols, monitoring existing field trials over the long term, and conducting full life-cycle cost analysis.

Polyurethane (PU) is widely used in construction, transportation, automotive products, decorative materials, and related industries because its molecular structure can be tailored to diverse service requirements. This versatility has stimulated growing interest in polyurethane-modified asphalt for pavement engineering. This review examines the chemical structure, reaction mechanisms, and principal synthesis routes of polyurethane-modified asphalt and discusses polyurethane-modified emulsified asphalt, polyurethane composite-modified asphalt, and polyurethane-modified asphalt mixtures. Engineering applications in permeable pavements, bridge and tunnel surfacing, as well as crack and pothole repair are also considered. The review further addresses green in situ polymerization, high-content polyurethane systems, waterborne polyurethane, interfacial adhesion, bio-based formulations, recycled asphalt mixtures, and life-cycle performance. The available evidence indicates that polyurethane can improve high-temperature stability, durability, fatigue resistance, mechanical strength, adhesion, and aging resistance. In suitable formulations, it can also reduce production temperatures and construction-related emissions. Economic feasibility, unresolved technical issues, and future research priorities are discussed at the end of the review.