Transport for NSW director general Les Wielinga revealed the price tag under questioning at a public hearing in Sydney this afternoon.

It is the first time a dollar figure has been put on what it will cost to keep dozens of towns and cities across NSW, Victoria and Queensland connected by rail.

XPT’s travel between Sydney, Brisbane, Casino, Grafton, Dubbo and Melbourne and stop at dozens of stations along the way.

There has been speculation the service could be axed given the cost of rebuilding or replacing the trains, the majority of which are now nearly 30 years old despite being designed to last just 25.

Refurbishing existing passenger cars and replacing the locomotives would require about $450 million, Mr Wielinga said, while buying higher-speed tilt trains would add “probably a couple of hundred (million) more” to the bill.

The estimate was met with prolonged silence from the committee of MPs questioning the transport bureaucrat.

“It’s a fairly significant investment and it’s a critical decision,” Mr Wielinga told them.

He said a decision on whether the investment was justified was a decision for government.

He also would not say if he agreed with a recent report by former NSW Premier Nick Greiner that suggested the government consider privatising the service or replacing CountryLink trains with coaches.

The government has not ruled out drastic changes.

If it decides to keep CountryLink in public ownership, a decision on whether to refurbish or replace the fleet may not be made until early next year, meaning the ageing trains will be forced to run for even longer.

“Some of these trains are many, many hours above their original design life but maintenance is keeping them going,” Mr Wielinga said.

The XPT fleet was designed to travel 6.25 million kilometres but by the end of last year had notched up nearly 10 million. The passenger cars are so outdated they don’t even have power points for phone chargers or laptops.

The ageing fleet, inconvenient timetables and consistent inability to meet the 78 per cent on time target are seen as barriers to boosting passenger numbers.

Some 1.9 million people travelled on a CountryLink train last year, down from 2.2 million a decade earlier.

CountryLink acting general manager Matthew Coates told today’s hearing until recently, just 10 per cent of trains travelling between Sydney and Melbourne had been arriving on time. Some had been regularly arriving up to an hour-and-a-half late.

He also poured cold water over a suggestion that allowing CountryLink to transport freight could reduce its burden on taxpayers.

“At the moment, our luggage carrying capacity is fairly well utilised so on the existing service, it would be difficult to undertake any carriage of any goods of significance,” he said.

Mr Coates also declined to comment on CountryLink’s potential privatisation or replacing trains with coach.