Singular sort of traffic (3,3)

I believe the answer is:

one way

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

(Other definitions for one way that I've seen before include "permitting no U-turn" , "getting no comeback?" , "Description of certain roads" , "Perhaps unrequited" .)

I've seen this clue in the Evening Standard.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.