Suddenly the traffic light looks so archaic.  Yes, the Virtual Wall is a concept, but regardless it could save lives, especially in cites like NYC, where cabs and other motorist race towards the lights to hit unassuming pedestrians crossing on flash walking sign.  One problem, though: lasers need something to reflect off of to be seen.  Perhaps man holes could be repositioned in an elongated fashion and spew steam up to catch the laser beams.

[Yanko]