This invention relates to traffic control systems primarily for controlling {HEAD ~ city traffic}, in {TAIL ~ a grid} of streets, secondarily, for street and road intersections presently controlled by stop signs 
This invention relates to traffic control systems primarily for controlling { HEAD ~ city traffic } , in { TAIL ~ a grid } of streets , secondarily , for street and road intersections presently controlled by stop signs
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH