The picture comes from this Quora thread on "the best new products that people don't know about." And it looks really cool! Though it also would require drivers to look at the traffic light for slightly longer to assess how much sand is left in the hourglass, and how fast it's running out. The result might be more distraction rather than more usable information. Wouldn't it be easier to just have a countdown, with the numbers rendered in green, yellow or red?
(Via Marginal Revolution.)