A major tree-trimming and removal programme started yesterday.
Officials intend to remove four trees which are rotten inside, while the rest will be trimmed and faced.
Downer EDI Works vegetation supervisor Beven Shanks said the project was "a major job" but one which was badly needed.
There were fears some of the rotten trees could fall over in high winds, endangering the public.
A large tree-trimming and facing machine was put to work on the first trees yesterday in an exercise Mr Shanks said would take all week, weather permitting.
Traffic lights have been erected at either end of the line of trees and motorists can expect delays of 10 minutes every hour.
The entire stretch of State Highway 8 would be closed for 20-minute spells when each of the four trees was felled so staff could clear the road.
