Crossword Genius

The only system for avoiding head-on collision? (3-3)

Ross

I believe the answer is:

one-way

I'm a little stuck... Click here to teach me more about this clue!

'avoiding head-on collision?' is the definition.
I can't tell whether this defines the answer.

'the only system' is the wordplay.
'the only' becomes 'one' (I've seen this in another clue).
'system' becomes 'way' (I am not sure about this - if you are sure you should believe this answer much more).
'one'+'way'='ONE-WAY'

'for' is the link.

Can you help me to learn more?

(Other definitions for one-way that I've seen before include "Not allowing reverse motion" , "Allowing travel in one direction only" , "Allowing movement in one direction only" , "Street allowing traffic in single direction only" , "Allowing no return movement" .)

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app