Discerning drivers can decide if the message is ABOUT or DIRECTED TO vampires. Personally, I like to think it's all about the department of transportation warning an army of vampires about a disturbingly vampire-unfriendly part of the highway.
At least now I know the default password for these machines. The first one we found died (I assume it ran out of solar power?) before we grew the balls to go change it. Thankfully, the second one was still running, and although I had a lot of trouble typing everything in total darkness, the home keys on the standard PC keyboard saved our evening!
It's pretty funny to think that tomorrow, no one will know about the boring detour that these signs were warning drivers about prior to my shenanigans.
Here's the inside of the box where you enter the password and wordings.