A database that represents the road network is used to determine locations where an intersection of roads is located at the bottom of a hill and then, {HEAD ~ precautionary action data} is added to {TAIL ~ the database} to indicate such locations 
A database that represents the road network is used to determine locations where an intersection of roads is located at the bottom of a hill and then , { HEAD ~ precautionary action data } is added to { TAIL ~ the database } to indicate such locations
OTH OTH OTH OTH OTH OTH OTH OTH OTH 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 HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH