To remind drivers to drive carefully during the rain in Papakura, New Zealand, the local government put out a rather disturbing billboard that bleeds when it rains. The billboard may be terrifying, but apparently it's effective: there hasn't been a fatality since.
BuzzFeed has the video clip: Link [embedded YouTube]
This infers that all fatal accidents are from human error but since they're not I say this is pure coincidence.
Because we all know that correlation = causation!