Crossword Genius

A contribution to road safety, one digging up part of the pavement? (4,5)

Ross

I believe the answer is:

kerb drill

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

'pavement?' is the definition.
Both the definition and answer are singular nouns.
Perhaps there's a link between them I don't understand?

I can't explain the rest of the clue.

Can you help me to learn more?

I've seen this clue in The Guardian.
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.