Regular street sweeping to clear glass, debris, and gravel etc from streets and cycle paths. Combine with a campaign to reduce glass debris, add more bottle recycling points etc.
How about the dcc mandating that glass bottles can’t be sold near student areas?
(On reflection I am not sure how much that would help, since it is probably a very small number of people who deliberately break glass and they might make special trips to other parts of town to buy bottles for this purpose…!)