Wow scary yet amusing stuff. Like the lorry snow bomb. Could have had a similar moment couple of years back, went to visit a friend who lives on an island in the Thames. It was December cold, snowy and icy (yes even in London). A small bridge connected the road and island and I got up it eventually then at the top wondered what to do as looking down it was all icey and then there was a wall. I was stuck. I actually thought I was going to lose control and slide down, then feared reversing and ending up sliding backwards onto the main road and getting hit. Had a panic, real girl moment and didn't know what to do then decided to call the boyfriend at the time for some advice and thankfully all was ok.