Long walk needing transport and parking (5)
I believe the answer is:
tramp
'long walk' is the definition.
(I've seen this before)
'transport and parking' is the wordplay.
'transport' becomes 'tram' (tram is a kind of transport).
'and' says to put letters next to each other.
'parking' becomes 'p' (abbreviation on road signs).
'tram'+'p'='TRAMP'
'needing' acts as a link.
(Other definitions for tramp that I've seen before include "Vagrant, hobo" , "woman who's promiscuous?" , "Walk with heavy steps like hobo" , "Disreputable wanderer" , "Tread heavily (on)" .)