to provide {TAIL ~ a safe central traffic control system} that can handle emergency vehicles without {HEAD ~ difficulty} 
to provide { TAIL ~ a safe central traffic control system } that can handle emergency vehicles without { HEAD ~ difficulty }
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD