THE president of a planning advocacy group says an airport at Badgerys Creek can't be built in "glorious isolation", but needs to be supported by links to Sydney's existing infrastructure network.
David Ryan, president of the NSW division of the planning institute of Australia, said the organisation has always supported a second airport at Badgerys Creek.
"We play an advocacy role on behalf of the planning industry and we have a long-standing position of support for the airport," Mr Ryan said. "And of course it would need all the logical connections to transport, including its own train station, which would be an extension of the south-west rail link and a connection to the M7. But exactly how these connections are created is something that needs to assessed by proposed engineering and feasibility studies."
Economic geographer Phillip O'Neill, a research fellow at the Urban Research Centre said an airport is a major infrastructure investment and in turn it generates a lot of infrastructure demands.
"There is almost no infrastructure there at the moment," Professor O'Neill said.
"If you take Elizabeth Drive west from Liverpool, once you reach Cowpasture Road it ceases to be a genuine arterial road and becomes a rural laneway."
He said that a lot of people did not realise that Liverpool's central business district was as close by road to Kingsford Smith Airport as it would be to an airport at Badgerys Creek and once the M5 was expanded and WestConnex built, access to Kingsford Smith would be enormously improved.
"The problem with Sydney airport is the traffic congestion surrounding it, but Sydney Airport corporation is working improving access to it.
"So the real question is whether it is desirable to have two airports in Sydney, with each of them costing vast amounts in infrastructure spending and each of them running below optimum capacity."