Virtual wall traffic light.

4,000+/year lives could be saved every year on our busy roads,

http://www-fars.nhtsa.dot.gov/Main/index.aspx

http://en.wikipedia.org/wiki/United_States_military_casualties_of_war

if this affordable gadget, was given a green light.







Alternately, green light is given to the old fashioned, incoherent, improficient, and almost equally costly technology.