"We have got on-demand movies, we want on-demand transport," Transport Minister Andrew Constance declared on Wednesday, as he announced a trial of so-called on-demand buses, trains and ferries by the private sector next year.

While the deregulation of ride-sharing had opened the way for buses of 12 seats or less to be booked by commuters, Mr Constance conceded that changing a suburban and regional train network that is heavily reliant on timetables into one more geared to on-demand services would be a challenge.

"I want to do away with timetables. Technology will take us to that point, so we are going to trial this next year and see what happens," he said.

"One of the great advancements that we will see over the next 12 months is the piloting of on-demand so people will be able to order a bus to their front door."

In taking a swipe at unions, he also indicated he was open to private companies such as Keolis Downer tendering for lucrative Sydney contracts held for decades by the government-owned State Transit Authority when they expire from 2018.

"Eighty per cent of the bus services in the state are provided by private operators. What we are seeing is a difference in the performance between some of those operators and the STA," he said.

"So I would be more interested in hearing from the union what they are going to do to improve on-time running."

However, the Rail, Tram and Bus Union (RTBU) demanded the government "come clean" on whether it plans to privatise bus services held by STA.

And the union said Mr Constance's plans for on-demand buses and trains was "little more than a thought bubble" lacking in detail.

"The union has been calling for memory timetabling for years and we'd still like to see that happen, but we can't see how a service that works 'on-demand' would work," RTBU state secretary Alex Claassens said.

Since holding a "Future Transport" summit in April, the Transport Minister has sought to stamp his mark on the portfolio by ramping up his focus on the use of technology to enhance public transport services in the state.

"[Technology] is taking it to a turn-up-and-go service," he said on Wednesday.

The $20 billion-plus metro train line under construction in Sydney will not operate to a timetable; instead, driverless trains will run on the line every four minutes that will eventually extend from the city's northwest to Chatswood, the CBD, Sydenham and Bankstown.

Mr Constance said ride-sharing legislation that had passed earlier this year deregulated the booking market for buses of 12 seats or less, which was especially important for regional areas.

"The local club courtesy bus might be transformed into something more broader in terms of providing transport services from community to community," he said.

"You might just get online and book a service and the next day it will be there on your front door. The key point is that the information and the bookings can provide better planning. So you might get, for argument's sake, 10 people in a couple of streets who might want a service the next day."

However, the prospect of more on-demand transport services also has implications for the conditions of drivers and other staff, who will inevitably be required to become more flexible.

Mr Constance said the point-to-point transport market was changing and technology would result in the automation of vehicles, "which is going to change the workforce again so we need to plan for that".

He also announced the government was teaming up with Twitter to allow train passengers to receive personalised messages from the online networking service alerting them to disruptions on the rail network.

It follows the government opening up data from the electronic ticketing system Opal to companies to develop real-time apps and other technology.

Mr Constance was forced to defend the government from suggestions it was allowing a private company access to personal data that could be used to tailor advertising.

The challenge was for customers to be aware of what they were doing online but Twitter users would be "happy to get this pop-up information about their journey", he said.

Twitter's head of business development, Jenny Goodridge, declined to comment on whether the company was attempting to gain information about users to make the online networking service more attractive to advertisers.

"We respect the privacy of that information. What we are looking to do is help people ... to deliver that better customer service experience," she said.