{TAIL ~ threshold} determining means for determining a velocity threshold value functionally related to {HEAD ~ said crash displacement value}; and 
{ TAIL ~ threshold } determining means for determining a velocity threshold value functionally related to { HEAD ~ said crash displacement value } ; and
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH