The government declined to release the traffic modelling to the Herald.
It said it was investigating measures to keep traffic flowing, including changes to bus lanes to give public transport priority and improve travel times.
Coalition roads spokeswoman Natalie Ward said Labor had been in power for six months and was already showing it could not deliver major infrastructure correctly.
“If this is such a massive issue, the minister for roads should have already ordered his new [Transport for NSW] secretary Josh Murray to find a solution,” she said.
The Rozelle interchange, which is part of the $17 billion WestConnex project, will connect the recently opened M4-M8 Link between St Peters and Haberfield, the City West Link, the Anzac Bridge, Iron Cove and, by 2028, the planned $7.4 billion Western Harbour Tunnel.
The government has indicated that full relief from congestion on major inner-city roads will not occur until the opening of the Western Harbour Tunnel, which will allow motorists to bypass the Anzac Bridge and Western Distributor to get to and from the north shore.
Transurban, which operates WestConnex, said this month that congestion on the Anzac Bridge and Victoria Road would remain a problem until the Western Harbour Tunnel opened in 2028.
Ahead of the opening of the Rozelle interchange, Transport for NSW is integrating electronic road signs on the Western Distributor to provide motorists real-time speed limit and lane changes, and road incident alerts.
The government said work on other improvements to the Western Distributor such as changes to an off-ramp and an intersection in Pyrmont would also begin within the next few months.
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