The NSW government has announced it will introduce thousands of new transport services in Sydney from November 26.

It has invested $1.5 billion into new weekly train, bus and ferry services in an attempt to shorten travel time for commuters and meet demand, as part of the More Trains, More Services program.

The ramp-up will see 1500 new weekly trains moving about the city, including 750 additional weekend trips.

As a result, 71 per cent of train stations can expect a train every 15 minutes (as a minimum) between 6am and 11pm.

There will also be 7000 new bus services across the northern beaches, eastern suburbs, inner west, lower north shore and northern suburbs, and Macarthur and the Hills districts.

“These changes are huge. We have better aligned bus services to connect with trains services, added new routes, improved existing routes, reduced journey times and ultimately maximised the network to meet the growing demand,” Transport minister Andrew Constance said in a statement.

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More than 140 extra weekly ferry services have also been added, including new routes between the east, lower north shore, inner west and the city.

Constance said the changes would help move towards a "turn up and go" service.

“We are going to make sure everyone knows these timetable changes are coming, so from today, customers can expect to see extensive advertising with plenty of information and announcements at stations, ferry wharfs and on buses across the public transport network,” he said.

The government is forecasting a 20 per cent increase in train users across public transport by 2021.