A 44 week scheme to improve safety on Richmond Hill starts next week.
The road will be closed to traffic this weekend to prepare before full works begin on Monday.
Over the weekend, the road will be closed from Spring Valley roundabout to Mount Murray Back Road, apart from for residents and emergency vehicles.
Richmond Hill will re-open at midnight on Sunday with traffic restricted to one lane in each direction and a 30 miles per hour speed limit will also be in place from Spring Valley roundabout to the top of Richmond Hill.
Work should be completed by December.