In addition to the Hazmat issue mentioned below, tunnels have a bad record when fires break out inside them. E.g. the Kaprun disaster [0] which killed 150 peopl

In addition to the Hazmat issue mentioned below, tunnels have a bad record when fires break out inside them. E.g. the Kaprun disaster [0] which killed 150 people, and the Gotthard Road Tunnel [1] fire, after which the use of large vehicles was constrained. [0] https://en.wikipedia.org/wiki/Kaprun_disaster https://en.wikipedia.org/wiki/Kaprun_disaster [1] https://en.wikipedia.org/wiki/Gotthard_Road_Tunnel#2001_collision_and_fire https://en.wikipedia.org/wiki/Gotthard_Road_Tunnel#2001_coll...