Street along with a road guide (8)
I believe the answer is:
standard
'guide' is the definition.
(thesaurus)
'street along with a road' is the wordplay.
'street' becomes 'st' (abbreviation).
'along with' becomes 'and' (I've seen this in another clue).
'road' becomes 'rd' (abbreviation).
'st'+'and'+'a'+'rd'='STANDARD'
(Other definitions for standard that I've seen before include "Ordinary Level?" , "sort of lamp" , "Flag - norm" , "Normal; flag" , "Flag - pattern - guide" .)