The Sydney Harbour Tunnel is now closed because of an overheight truck at the Cahill Expressway, Wooloomooloo.
Southbound lanes of the tunnel are closed off, with motorists urged to avoid the area entirely.
Those planning to travel south through the tunnel are being diverted onto the Harbour Bridge.
Traffic crews are working to move the truck, which has caused three of four southbound lanes to close at the Cahill Expressway, with the truck causing some damage to the overbridge at Art Gallery Road.
For more info visit www.livetraffic.com.