It is high time for a Sign Language
Universal languages have their place in the day-to-day life. Traffic signs will make self-driving cars work.
But isn't that argument the wrong way around? Traffic signs are just used because they're already there and have to be obeyed as long as there are still human drivers. If we were to design self-driving cars first, wouldn't we use a more precise and efficient method of communication, like by interconnecting all cars or centralize the routing at intersections? Nothing against Sign Language or the idea of universal languages in general though.