Target section of north-south artery (3)
I believe the answer is:
aim
I believe this clue is a double definition.
'target' is the first definition.
(both can mean a goal or purpose)
'section of north-south artery' is the second definition.
(resembles A1(M), part of England's A1 road)
(Other definitions for aim that I've seen before include "Point or direct, a weapon say" , "Object; intend" , "Direct; intention" , "Plan" , "Set sights on, say target" .)