Commuters will have to wait until 2017 or 2018 for two extra morning services the Baird government is promising between Parramatta and Central.

The Premier, Mike Baird, and the Transport Minister, Gladys Berejiklian, announced the extra express services on Monday alongside a pledge to spend $100 million on upgrading ferry services along the Parramatta River.

NSW Premier Mike Baird, Parramatta MP Geoff Lee and NSW Minister for Transport Gladys Berejiklian leave Parramatta Station after announcing new transport measures on Monday. Credit:Daniel Munoz

The money for ferries will buy an extra four vessels, a new wharf at Rhodes, and upgrades to eight different ferry wharves.

The modesty of the rail promise - the services are unlikely to be available for a new planned timetable in 2016 - underlines the difficulty of trying to run extra trains on Sydney's current rail network.