Transport for NSW and Roads and Maritime Services (RMS) are developing a business case for the extension which it will present to government some time in the 2016-17 financial year.

This comes after the RMS confirmed the eastern F6 was a better option for any extension than building it along the A6 route, which starts at Heathcote and heads through Bankstown.

“It provides more effective links to the airport and Port Botany, as well as better access to the city Sydney’s north and west via WestConnex,” said NSW Roads Minister Duncan Gay.

The eastern route would also have a smaller impact on property given the area has been reserved since 1951.

RMS will be collecting soil and rock samples along the F6 corridor over the coming months which will help develop design options and costings for inclusion in the business case.

However the business case does not mean the F6 will go ahead.

“Any decision on prioritising the F6 will be considered in the context of the NSW Government’s transport infrastructure program, including other motorway, light rail and Sydney Metro projects, once the business case has been submitted,” Mr Gay said.

Parliamentary Secretary for the Illawarra Gareth Ward said the business case would work out how the road could be delivered, “whether that be in stages, whether that be cut and cover or tunneling or both.”

Cut and cover is when a trench is dug and the tunnel is constructed inside it.

Mr Ward said he would continue to push for the extension to go ahead.

“For decades people have talked about the F6 and I stuck my neck on the line and said this is something that would make a real difference to the lives of people of the region, particularly the 22,000 people who commute by road from the Illawarra to Sydney every day,” Mr Ward said.