The road side data exchange net includes a plurality of {HEAD ~ road side data exchange devices} set on {TAIL ~ neighboring roads} separately 
The road side data exchange net includes a plurality of { HEAD ~ road side data exchange devices } set on { TAIL ~ neighboring roads } separately
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH