As some streets joined still without width (3-3)
I believe the answer is:
one-way
'as some streets' is the definition.
'joined still without width' is the wordplay.
'joined' becomes 'one'.
'still' becomes 'ay' (archaic term for 'always').
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'width' becomes 'w'.
'one'+'ay'='oneay'
'oneay' placed around 'w' is 'ONE-WAY'.
(Other definitions for one-way that I've seen before include "Only travelling in the same direction" , "Single-directional like some streets" , "This street allows only single traffic flow" , "Allowing movement in one direction only" , "Allowing motion in a single direction" .)