The control system guides {TAIL ~ the moving travel zones} through {HEAD ~ the empty zones} of the cross roads without stopping 
The control system guides { TAIL ~ the moving travel zones } through { HEAD ~ the empty zones } of the cross roads without stopping
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH