Introduction:
Zhaohui Joey Yang, Professor, Department of Civil Engineering, University of Alaska Anchorage

Cold regions cover 50% of the world’s total land area, including Alaska, Canada, Finland, Norway, Sweden, a vast portion of China and Russia, and all the northern tier of the continental United States in the northern hemisphere. Infrastructure development in cold regions encounters great technical challenges due to ground freeze‐thaw or permafrost degradation resulting from anthropogenic activities and climate change. New transportation infrastructure on embankments, such as high‐speed railways and highways, requires higher geometry and performance standards and hence helps advance soil engineering research related to cold regions applications. Under this background, the symposium on Transportation Soil Engineering in Cold Regions (TRANSOILCOLD) was initiated by a group of researchers and practitioners from China, Russia, and the United States under the leadership of Prof. Jiankun Liu, Sun Yat‐sen University, China. The symposium was first held at Xining, China, in 2013, and subsequently at Novosibirsk, Russia, in 2015, and at Gui‐de, China, in 2017.

TRANSOILCOLD2019 was successfully held 20 –23 May 2019, aiming to provide a broader view of the challenges and problems faced by designers, contractors, and infrastructure owners during the planning and building of transport infrastructure in cold and arid regions. In particular, it provided a rare opportunity to learn the work from our Russian colleagues. Among the many excellent studies presented by more than 200 participants worldwide, seven articles were invited and subjected to this journal's strict peer‐review process before being accepted to be published in this special issue. These articles provide the latest progress in cold regions transportation soil engineering research by authors from Canada, China, Russia, and the USA. The topics encompass artificial ground freezing technology advancement and applications in China’s urban development, fundamental studies of soil engineering properties during freeze‐thaw with new experimental techniques, performances of ice‐rich soil embankment stabilized with additives, design procedures of thermal stabilization of road embankment, and innovative technologies to control frost heave in chilled liquid gas pipelines.

This special issue is of great value to researchers and practitioners in cold regions transportation soil engineering. Special thanks go to Prof. Jiankun Liu and Dr. Andrei Petriav from Emperor Alexander I St. Petersburg State Transport University for their assistance in identifying these excellent articles.