http://www.youtube.com/watch?v=SnI0RFLJiqE
This 3150 m long tunnel in Russia is the longest in-city tunnel of Europe. There is a river running over it and water leaks at some points. When the temperature reaches -38 degrees like it did this winter, the road freezes and the result is the attached video taken during a single day with the tunnel camera.
Think yourself lucky you're not a passenger on the bus!