Red Means Go

Jalopnik lists ten ways that "city planners" screw up traffic lights. Link here. City planners are getting unfairly blamed here, but we'll go with it.

I didn't know that in 1966 China almost switched the colors of traffic lights as part of the cultural revolution. Red meant go and green meant stop. Details here. Red, the color of the revolution, should not be associated with stopping. Red means go associates the color with progress! And, if enacted, lots of crashes. However, it is not obvious that the color of the lights makes a difference in many cases:

Explain This Traffic Light

xkcd: "There is an intersection I drive through sometimes that has a green arrow, a red light and a 'no turns' sign all on one pole. I honestly have no idea what it is telling me to do."

Source: http://xkcd.com/1116/