Imagine this: You just went to bed, it's 1 am and suddenly it's bright as day in your room, flashing lights and terrible noise outside. Sounds like a UFO landing. But you look out of the window and see a big monstrum of a machine out there and four men carrying spray cans and a big board around. Sounds like a prank in the making. But in the morning you wake up and see strange signs on the road.
Here's the question for you: What are these?