These proceedings include papers presented at the 7th International Symposium on Tunnel Safety and Security (ISTSS) held in Montreal, Canada, 16-18th in March 2016. The symposium is well established in the tunnel fire community and the success of ISTSS is a tribute to the pressing need for continued international research and dialogue on these issues. These proceedings provide an overview of emerging research and regulatory actions coupled to state-of-the-art knowledge in the field of safety and security in undergrounds structures. This ISTSS regularly attracts over 230 delegates from all parts of the world and represents an arena for researchers to discuss safety and security issues associated with complex underground transportation systems. We see that active fire protection has become a major field of interest. Further, risk and engineering analysis continues to be an area that attract many papers. Also the interest in new energy carriages (vehicles with new type of propellant) in tunnels increase and will in near future become one of the most important research fields. Numerous renowned researchers and engineers have contributed to these and other topics at this symposium for which we are very thankful. Fire related issues still attract many presentations but the focus has shifted towards technical solutions that can mitigate the fire development should a fire occur. The enormous costs for underground structures forces engineers to design alternative solutions. The sessions that have greatest focus on mitigation of fire development include those dealing with the effects of ventilation systems, active and passive fire protection, fire fighting and human behaviour.