South Coast rail commuters could end up paying more for their train ticket so the government can avoid a multi-billion dollar budget blowout.
According to "sensitive" documents obtained by the Sydney Morning Herald, Transport for NSW is looking at ways to find $7 billion in annual savings by the end of the decade to reduce the funding pressure on government.
If nothing was done, the cost to government of providing public transport services would almost double over the next 10 years - from $5.8 billion in 2018 to $9.6 billion in 2028.
Among the measures under consideration are changes to the fare structure.
The document suggests Transport for NSW could "adjust benefits and concessions for public transport and introduce tiered pricing for enhanced services to reflect a more equitable user-pays framework".
.. it would be 'more equitable to charge more for travelling longer distances in that it means all users pay a similar price per kilometre travelled'.Independent Pricing and Regulatory Tribunal
This could lead to an increase in the fares for South Coast rail commuters travelling between Wollongong and Sydney, which are substantially cheaper on a per kilometre basis than those making shorter trips.
The shortest Opal card fare band is for 0-10 kilometres, which is equivalent to 35 cents a kilometre.
The Wollongong-Sydney commute falls under the longest band of 65-plus, which is 13 cents a kilometre.
That means those making the longest trips are getting a better deal than those only travelling for a few stations.
If that 35-cent rate was charged a Wollongong-Sydney fare would be $22.75 one-way.
The Independent Pricing and Regulatory Tribunal is conducting a review of Opal fares.
The body has stated it could be "more equitable to charge more for travelling longer distances in that it means all users pay a similar price per kilometre travelled".
Transport for NSW secretary Rod Staples said no government policy decisions have been made.
"This is sharing with them thoughts and opportunities," he said.
"In terms of any major policy decision, we'll have to do that on its merits and I'll do that in consultation with the ministers and Premier."