{HEAD ~ a communication device} arranged in {TAIL ~ the second vehicle} and which communicates the position of the second vehicle as determined by said second positioning system to the first vehicle 
arranged in
{ HEAD ~ a communication device } arranged in { TAIL ~ the second vehicle } and which communicates the position of the second vehicle as determined by said second positioning system to the first vehicle
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH