This podcast from Transport Security International Magazine discusses the major threats to tunnel security and explores mitigation strategies. Two experts, Simon Brimble and Ian Chaney, offer insights into how tunnels can be designed and operated to withstand threats such as terrorism, fire, flooding, theft, and cyberattacks. The podcast highlights the importance of comprehensive security planning, including the use of physical barriers, electronic detection systems, hardened access points, and robust cyber security measures. The experts emphasize the need for a risk-based approach to tunnel security, acknowledging that complete protection is not always feasible. They also reassure readers that tunnels are often more secure than people imagine, with measures in place to ensure the safety of passengers and the smooth operation of these vital transportation systems.