Commuters should prepare for delays and extra travel time through to Tuesday August 6 as work continues on the Tarro Rail Bridge at the New England Highway, Transport for NSW says.
The latest work to repair the bridge pylons and southern abutment, which will help preserve the road over the 60-year-old bridge, began on Saturday August 3.
The work was planned to coincide with a three-day closure of the rail corridor for track maintenance, Transport for NSW said.
Traffic will be disrupted, with one lane open in each direction and a reduced speed limit of 40 kilometres per hour.
Vehicles more than three and half metres wide and/or weighing more than 69 tonnes were not permitted to drive over the bridge, and would be diverted through an alternative route, Transport for NSW said.
"Motorists will experience delays in the area, particularly on the Monday and are reminded to allow extra travel time or work from home, if possible," a statement from Transport for NSW said.
For the rest of the weekend and on Monday, regular train services will be replaced with buses.
Depending on weather conditions, the maintenance work is expected to be completed by Tuesday August 6 at 5am.
Transport for NSW said work is also scheduled for three other bridges on August 4, including the Sandgate Rail Bridge, Industrial Drive Rail Bridge and Kooragang Bridge.
While impact from these three bridges would be minimal, roads were likely to be busier due to route diversions caused by the Tarro Bridge works, Transport for NSW said.
"Motorists are advised to allow plenty of additional travel time and to follow the direction of signage in place," Transport for NSW said.
For updates on road closures visit Live Traffic NSW at livetraffic.com/incident-details/202495