This book gathers the proceedings of an international conference held at Empa (Swiss Federal Laboratories for materials Science and Technology) in Dübendorf, Switzerland, in July 2020. The conference series was established by the International Society of Maintenance and Rehabilitation of Transport Infrastructure (iSMARTi) for promoting and discussing state-of-the-art design, maintenance, rehabilitation and management of pavements. The inaugural conference was held at Mackenzie Presbyterian University in Sao Paulo, Brazil, in 2000. The series has steadily grown over the past 20 years, with installments hosted in various countries all over the world. The respective contributions share the latest insights from research and practice in the maintenance and rehabilitation of pavements, and discuss advanced materials, technologies and solutions for achieving an even more sustainable and environmentally friendly infrastructure.

This synthesis report will be of interest to state, local, and federal agency pavement materials, design, and construction engineers, as well as pavement research engineers and scientists. Those with supervisory oversight for pavement programs will also find it of interest. It describes the current practice for methods to achieve rut-resistant durable pavements. The synthesis documents current experience with permanent deformation of asphalt pavements and identifies methods to improve performance. Information for the synthesis was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search using domestic and international sources. This report of the Transportation Research Board describes the extent of the rutting problem on the National Highway System, pavement mixture design issues, and the design of rut-resistant mixtures. In addition, alternate mixture types, including stone matrix asphalt and porous asphalt, are discussed, as well as international approaches to mixture design. Finally, the construction of rut-resistant mixtures, including the role of quality control and quality assurance methods, are discussed. A summary of permanent deformation causes and solutions is included in the appendix.