Melbourne doesn't need another airport, it needs parallel runways (on both trajectories due to the wind patterns). There was a long term plan to provide alignment and space for future parallel runways (the alignment is still indicated on the Melways - although that's not much of an indicator of future plans). I'm not sure if that potential has been sold off now due to airport privatisation and the consequent huge expansion in commercial wharehouse/factory land sell-offs around the airport... if so, very sad for the future of Tulla.