**Preface**

With the growing demand for passenger transport and freight, the design, construction, and maintenance of transportation infrastructure now face new development opportunities and challenges. Under the combined effects of traffic load and environmental factors, the performance and serviceability of road pavement deteriorate over time. Improving the durability and surface characteristics of road pavement remains an important research goal. In addition, emerging technologies and societal changes put forward a high demand for green pavement, environmentally friendly construction and maintenance, and smart and intelligent infrastructure. Traditional pavement materials cannot meet the needs of our evolving society. In recent years, the advantages of new materials in improving road performance have attracted extensive interest from industry professionals and academia. Polymer materials exhibit high thermal stability, superior mechanical properties, as well as corrosion and chemical resistance. They are widely used in important fields of the economy such as aerospace, biomedicine, transportation, electronics, etc. With the development of material science and technology, polymer materials demonstrate great potential for road engineering applications.

In order to succinctly summarize recent advancements in polymer road materials research and to promote innovation in this field, Professor Wei Jiang of Chang'an University collaborated with Professor Quantao Liu of Wuhan University of Technology, Associate Professor Jose Norambuena-Contreras of the University of B´ıo-B´ıo, and Associate Professor Yue Huang of the University of Leeds to co-organize the Special Issue titled "Application of Polymer Materials in Pavement Design".

This Special Issue comprises 17 research articles and 2 review articles, covering studies on both individual and composite polymer modifications. Topics include high-content polymer-modified bitumen, epoxy resin adhesives, SBS-modified bitumen, PE-modified bitumen, crumb-rubber-modified bitumen, and biopolymeric capsules and bitumen rejuvenators.

We wish to extend our appreciation to the *Polymers* editorial team for their valuable technical support and to the scholarly community for their great contributions to this Special Issue.

#### **Wei Jiang, Quantao Liu, Jose Norambuena-Contreras, and Yue Huang** *Editors*
