Traffic lights!

They're pretty much the sole reason I'm two minutes late to work every morning (trust me, it has nothing to do with me oversleeping). Let's face it. We wouldn't have to deal with these annoying signals if we all rode horses to work in the morning. But overpopulation means there are TOO MANY PEOPLE ON EARTH FOR EVERYONE TO HAVE A HORSE! True, six billion horses would create an entirely different set of problems (and most likely require a separate blog), but traffic lights would not be one of them. Also, there would be a decrease in air pollution.