Traffic conditions on Hexham Bridge will temporarily change on Monday night while Roads and Maritime Services (RMS) carries out biannual maintenance.
Southbound lanes on the bridge will be closed between 8pm on Monday, September 10 through to 4.30am on Tuesday, September 11.
Traffic will be diverted onto the northbound bridge, which will have one lane operating in each direction.
RMS will work in three shifts, weather permitting, to inspect and test electrical, mechanical and emergency system components on the bridge.
The pedestrian bridge will also be closed while the work is carried out.
Traffic control will be on site to ensure safety for pedestrians using the northbound bridge while the pedestrian bridge is closed.
The bridge will not be open to marine traffic while the work is carried out.
Motorists are advised to drive to the conditions, and follow the directions of signs and traffic control.
For the latest traffic updates download the Live Traffic NSW app, visit livetraffic.com or call 132 701.