The head of the state government's infrastructure advisory has criticised the Abbott government's refusal to fund public transport projects.

"I can't really understand the logic of saying we will only invest in a transport project if it involves bitumen as opposed to one that involves steel rails," Jim Betts, the chief executive of Infrastructure NSW, said on Tuesday.

'Public transport beyond the pale': Prime Minister Tony Abbott has been criticised as not being committed to public transport. Credit:Brendan Esposito

The Prime Minister, Tony Abbott, maintains it is not the federal government's role to provide funding for public transport.

He says public transport should be funded by the states, while the Commonwealth has a role in helping fund motorways and rail freight initiatives.