In order to maintain alternating nonstop traffic flow on the nonstop lane, three moving zones are marked along {HEAD ~ the fastroads} by {TAIL ~ signal emitting fixtures} operated according to signal progression principles 
In order to maintain alternating nonstop traffic flow on the nonstop lane , three moving zones are marked along { HEAD ~ the fastroads } by { TAIL ~ signal emitting fixtures } operated according to signal progression principles
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH