THE Rail Revival Alliance is running a train trip this Sunday through Ballarat, Maryborough and Geelong to raise support for inter-regional rail services.

The alliance is also celebrating 140 years of the opening of the rail line between Castlemaine and Maryborough - though the line is currently unusable. 

The group has hired a heritage diesel train to take 50 passengers from Newport to Ballarat, Maryborough, Geelong and finally to Southern Cross, Melbourne.

They aim to highlight how easy it is to travel between regional centres without going via Melbourne each time - though they are unable to travel as far as Bendigo because the Maryborough to Castlemaine track is in disrepair.

The Rail Revival Alliance aims to put pressure on the government to commit to reviving inter-regional rail services.

A government study done last year estimated the revitalisation of the lines between Geelong, Ballarat and Bendigo would cost nearly $1 billion.

"All we want is an 80km/h service in the country which would service these towns perfectly," alliance president Neol Laidlaw said.

Mr Laidlaw, an engineer, said reviving the old lines would cost much less than the government's estimate.

"We’ve costed the whole thing out at under 100 million," he said.

Mr Laidlaw said the current bus services between regional centres such as Geelong and Ballarat were "terrible" and were a disincentive to travel.

"The government has to spend money on public transport infrastructure," he said.

"One hundred years ago Victoria had the best motor system in the world, then cars came in," he said.

Mr Laidlaw said that now with increasing population figures in regional cities, it was time to have a better train service, which would also relieve population pressure in Melbourne.

"Melbourne is choking. You have to develop these country cities, because Melbourne is out of control."

He also said a better regional rail service would be good for students travelling for study in Geelong, Ballarat or Bendigo.

Mr Laidlaw said while the regional rail project was important, it was Melbourne-centric. Passengers from Bendigo to Geelong, for example, have to travel via Melbourne - a detour the Rail Revival Alliance thinks is inefficient and discourages people from travel.

He said the Rail Revival Alliance had "overwhelming" public support.

The Greens have backed the group's campaign, announcing an official policy for a five-city rail link between Bendigo and Geelong.