The Southern Freeway and Mt Ousley Road from Waterfall to Albion Park Rail will become part of the M1 Princes Motorway under the NSW government's scheme to rename major roadways.
Under the $20 million project, announced yesterday by Roads Minister Duncan Gay, the Princes Highway from Albion Park Rail to the Victorian border will become the A1.
The Sydney to Newcastle F3 and the Pacific Highway between the Queensland border and north of Byron Bay become the M1 Pacific Motorway.
The highway between Newcastle and Byron will be the northern section of the A1.
Mr Gay said the renaming of more than 60 routes across the state would bring NSW into line with the alpha-numeric system in use in Queensland and Victoria. The changes would see an M given to motorways, an A to routes of national significance and a B to routes of state significance. The routes would also retain their regular names, he said.
"The changes will mean drivers can be confident travelling along the eastern seaboard that the road numbers all follow the same pattern, ending the confusion between states," Mr Gay said.
The changes will start next March and be completed by December .
Mr Gay acknowledged the $20 million cost of the exercise was a large amount of money to spend on new signage, but added it would be money well spent.
"This has an economic benefit to the state, in that it allows our goods to move better, it helps our tourism, and it also has a safety outcome," he said.
"Eventually it will help our safety vehicles to be able to find their way quicker."
But the opposition said it was "complete madness", particularly when the government was cutting billions from the education and health budgets.
"The people of NSW want their roads fixed and they want them built, they don't want them simply renamed," acting opposition roads spokeswoman Penny Sharpe said.
Ms Sharpe dismissed suggestions the tourism industry would benefit from the changes.
"Tourists already seem to get around NSW quite fine on their own," she said.
"Most cars actually have a GPS these days.
"The Hume Highway will still be the Hume Highway ... This is a waste of time and money."