The technical session on Operational Safety of Underground Transportation Facilities on the 7th of May as part of the World Tunneling Congress 2019 in Naples was well-attended. The audience consisted of many ITA COSUF members and other delegates from the WTC 2019. In his opening word, ITA COSUF Chairman Max Wietek underlined that New Energy Carriers in combination with underground transportation facilities will lead to new operational safety risks and there is a need of new knowledge on how these new risks should be assessed and controlled. Some topics that were covered during te workshop were IT systems, monitoring, the refurbishment challenge that is facing Europe and various presentations on ventilation in rail and metro tunnels. The presentations can be downloaded here.