Have you ever wondered what sort of work goes into making a road sign? It's actually an intensive, ongoing process - one involving more than posting giant white lettering on a big reflective sign.
Traffic experts from around the world attend conferences on the creation of effective road signs. They do studies and experiment with visibility, legibility and understandable instructions for drivers whizzing by.
And yet... signs have defied more than a century of attempts at standardisation. And then there's just good old human error. Check out some of these humorous head-scratchers.