Retiree Ellen Karas is doing her best to avoid taking public transport from her home in the western Sydney suburb of Fairfield to the central city because of the difficulties she has had navigating the Opal electronic ticketing system.

And she knows of elderly people who are stocking up on paper tickets before the vast bulk of them cease to be sold for use on public transport in NSW on January 1.

"I know someone who bought 15 of them because it would do them well into the new year and they don't want to use Opal," she said.

The long list of challenges confronting senior commuters and those with disabilities in having to switch to the electronic ticketing system has been highlighted in a survey that shows just 27 per cent of the state's 314 Opal-enabled train stations have top-up machines.