traffic lights

why not make the top 2 lights on traffic lights
downward pointing triangles
like warning signs

red = stop

red & amber = stop

amber = stop

green = go

this would help those who are colour blind
and may make it more obvious what the sign means
the triangles could be slightly larger than the circle for go
a space could be left at the top for a future addition
a blue light ( see blue wave )

2007