Miss Brennan travels to the city twice a week to take part in a program at the Crows Nest studio, which provides support for artists with intellectual disabilities.

The comparative security of the bus over the train made it the best option for her parents Liz and Terry Brennan, so Australia Wide Coaches' decision to leave Orange later and Sydney earlier has upset them.

From October 14, the Orange to Sydney trip will be changed from a 6am to a 6.30am departure seven days a week. The return trip will be changed from a 5pm to a 3.40pm departure from Sydney Central from Monday to Thursday.

Mr Brennan said he would've like to have seen more consultation with customers.

"It's quite a significant thing for her," he said. "She's been doing it for 12 months or so now and she's doing some excellent work.

"Her independence has gone up. She's much more confident and she's got a whole new group of friends."

Mr Brennan said if she can't go on the bus, she can't go at all. "It's a security thing," he said.

Australia Wide Coaches operations manager Stefan Robinson said the earlier departure from Sydney was a response to customer demand to arrive home earlier in Bathurst and Orange.

Mr Robinson said the later time from Orange reflected the new roads and use of the new WestConnex tunnel, which made the journey quicker.

"There are minimal changes to the arrival times into Sydney," he said.

Australia Wide Coaches partnered with NSW TrainLink recently to provide a bus connection to the second Bullet train from Bathurst to Sydney.

The second Bullet train service started on September 16.

Mr Robinson said it made the decision to alter the timetable from October 14 easier.

"We can use the existing service or charter to TrainLink a separate vehicle according to load factors," he said.

Mr Brennan said his calls to the company have been ignored.

"The attitude seems to be 'it's a given' go and talk to someone else and forget about it," he said.