The cost of extending the F6 from Arncliffe to Loftus has been estimated at between $8.6 billion to $10.4 billion by a new study.
The study also revealed traffic on President Avenue, Kogarah, would increase with each stage of the F6 extension.
There would be a 26 per cent increase with the opening of stage one from Arncliffe to Kogarah, which would rise to 32 per cent with stage two to Taren Point and to 37 per cent with stage three to Loftus.
In contrast, traffic on Princes Highway at Rockdale would drop by nine per cent when stage one opened, reducing to 10 per cent and 12 per cent with subsequent stages.
Traffic on General Holmes Drive would decrease by five per cent over the three stages.
The study, commissioned by the Illawarra Business Chamber and NRMA, found the F6 extension would slash travel times between Wollongong and Sydney, with economic benefits of $677 million per year in 2031.
The F6 extension was one of five key road and public transport projects across the Illawarra region and southern Sydney covered in the study.
A report, titled Upgrading Road Connectivity between the Illawarra and Greater Sydney, was released on Thursday.
The report said the projects could unlock hundreds-of-millions of dollars in economic benefits and create thousands of new jobs.
Current travel times from Wollongong to Sydney in peak hour could take at least 90 minutes for the 85 kilometres journey, the report said.
The same journey from Newcastle – an extra 160 kilometres – was only 30 minutes longer.
The Wollongong to Sutherland leg took on average 45 minutes and the Sutherland to Sydney leg took about the same time but was far more variable.
The report said the F6 extension was expected to slash travel times in the morning peak by 27 minutes.
It said an indicative cost estimate for the first three stages was between $8.6 billion to $10.4 billion.
“It should be emphasised that this cost is indicative only and does not involve any input from RMS,” the report said
“This is a complex project and its final cost is dependent on a range of factors, not of least the extent to which tunnelling is required.”
The report also found:
- 30,600 (17 per cent) of Illawarra residents travel to Sydney for work each day.
- 15,800 workers from outside the Illawarra travel to the region each day for work.
- 80 per cent of northbound trips are by car; 20 per cent by public transport.
- The most significant bottlenecks on the Sydney to Illawarra journey are at Captain Cook, Tom Ugly and Alford’s Point bridges.