so, for years technology has held the promise of a solution...but we still have problems.
the FAA is afraid of another controllers' strike like in the early 80's...so instead of investing in first class people, they invest in machines.
how easy it would be to get a man, with a radio (that's RT to you) binoculars, and two big flags...one red, one green.
station them at each intersection. ATC is still responsible for the clearance to cross, but the guy with the flags could still stop you...he would be the backup set of eyes for atc from a differtent view point. if he gave you the red flag (illuminated at night) stop...PERIOD, green is good provided ATC has given the equivelent of green via radio.
Flag man is also maintaining a listenting watch on the radio.
ok, gvie the flag guy some high powered anti noise headsets too!
there would be no need for a new machine...just good people.