Black American providing transport (3)
I believe the answer is:
bus
'transport' is the definition.
(I know that bus is a more specific form of the action the transport)
'black american' is the wordplay.
'black' becomes 'b' (abbreviation as in pencil classifications).
'american' becomes 'US' (abbreviation for United States).
'b'+'us'='BUS'
'providing' is the link.
(Other definitions for bus that I've seen before include "Coach" , "People carrier" , "Mode of public transport" , "Means of public transport" , "Of projectiles; (go) mad (slang)" .)