This report includes the Proceedings of the 8th International Symposium on Tunnel Safety and Security (ISTSS) held in Borås, Sweden, 14-16th of March, 2018. The Proceedings include 41 papers given by session speakers and 16 extended abstracts presenting posters exhibited at the Symposium. The papers were presented in 12 different sessions. Among them are Fire Safety Engineering: Cases & Incidents, Fire Safety Engineering: The Aims, Fire Detection, Explosions, Risk Analysis, Fire Safety Engineering: Case studies, Ventilation, Fire Safety Engineering: State of the Art, Fire Dynamics, Fixed Fire Fighting Systems (FFFS) and Evacuation and Human Behavior.

Each day was opened by invited Keynote Speakers (in total six) addressing broad topics of pressing interest. The Keynote Speakers, selected as leaders in their field, consisted of Hans Brun, the Swedish Defence University, Dr Iain Bowman, Mott MacDonald, Canada, Dr Ying Zhen Li, RISE Research Institutes of Sweden, Dr Johan Lundin, WSP, Sweden, Allan Skovlund, Greater Copenhagen Fire Department, Denmark and Prof David Purser, Hartford Environmental Research, UK. We are grateful that the keynote speakers were able to share their knowledge and expertise with the participants of the symposium.