sash window draught proofing

[tarheelbaby]

I live in a Grade II property on a very busy main road.
Has anyone had brush pile draught-proofing installed on their sash windows? Does it work?
Also, I have interior cavity glazing for noise reduction. These are quite old now. Has anyone replaced this?

Yes. And yes it definitely helps. Other good options are magnetic pvc secondary glazing and thick thermally lined curtains.

Whoops. I meant for insulation mostly but it does help worh noise a bit too but not as much. Have you investigated whether you might be able to reuse the existing window frames and get double glazed acoustically insulating glass uniting put into them?