Lack of transport in southern metropolitan area (8)
I believe the answer is:
scarcity
'lack' is the definition.
(I've seen this before)
'transport in southern metropolitan area' is the wordplay.
'transport' becomes 'car' (car is a method of transport).
'in' is an insertion indicator.
'southern' becomes 's' (abbreviation).
'metropolitan area' becomes 'city' (a metropolis is a large city).
's'+'city'='scity'
'car' placed within 'scity' is 'SCARCITY'.
'of' is the link.
(Other definitions for scarcity that I've seen before include "Thinness" , "Shortage" , "Lack - dearth" , "Want" , "Something uncommon" .)