Road signs are pretty boring, albeit important. They tell us where to go, what to do and what we should avoid on the road. Road signs don't usually make us laugh – until people figured out that they could be altered in a number of ways.

Pasting a sign over another sign is a simple idea, but hacking into the digital road signs that warn us about traffic delays and road hazards is a whole new level of dedication to mishievous shenanigans.

Here are 19 of the funniest hacked digital road signs.