The 3,150 metre long Lefortovo tunnel, in Russia , (near POLAND ) is the longest in-city tunnel in Europe . It is nicknamed 'The Tunnel of Death'. See why, for yourself.
There is a river running over the tunnel and water leaks at some points. When the temperature reaches nearly 0C, as it does in winter in Russia, the road freezes and becomes as slippery as ...well...ice.
The result is the attached video which was taken during a single day with the tunnel surveillance camera.
Congratulations to the dual-carriage bus driver...imagine the passengers in the back...