Like special road system? Nothing unexpected before a journey's end (3-3)
I believe the answer is:
one-way
'like special road system?' is the definition.
(as in a one-way road)
'nothing unexpected before a journey's end' is the wordplay.
'nothing' becomes 'o' (looks like zero - 0).
'unexpected' becomes 'new' (new can mean unexpected or novel).
'before' means one lot of letters go next to another.
'end' suggests the final letters.
The final letter of 'journey' is 'y'.
'o'+'new'+'a'+'y'='ONE-WAY'
(Other definitions for one-way that I've seen before include "This road permits only a single flow of traffic" , "Kind of street where cars shouldn't meet head-on" , "This street permits traffic only in one entrance and exit (3-3)" , "Unidirectional" , "Street allowing traffic in single direction only" .)