When Dora Makaritis realised the route of the WestConnex motorway would run under the inner west suburb of Croydon, she immediately became concerned about the impact of digging a six-lane tunnel under her home.

So she asked the WestConnex Delivery Authority, multiple times, why the motorway would run under her suburb and not 300 metres north under Parramatta Road.

And she was told, multiple times, it had nothing to do with potential property development.

"We were told a couple of things," said Ms Makaritis. "One of them was that you could not travel 80 kilometres an hour under that [Parramatta Road] route," she said. "The route had to be a straight line, and not a zig zag."