TOLL roads must be considered to help fund crucial infrastructure, Business SA says. Chief executive officer Nigel McBride says the State Government and the Opposition should be open to the idea of a user-pays system. And Premier Jay Weatherill yesterday conceded the government was considering tolls on freight vehicles as part of a $1.1 billion Northern Connector project. Mr McBride said he had serious doubts the government could pay for a $46 billion transport infrastructure program without tolls. In a submission to the Productivity Commission's Public Infrastructure Inquiry, Mr McBride argues that the State Government "must be open to all types of infrastructure funding, including user charging" to encourage the private sector to invest. He told The Advertiser that the state was "behind the eight ball" on infrastructure, and that the Government's "bold and ambitious plan has to be paid for somehow." But he emphasised that he was not necessarily talking about commuters paying a toll to use roads, and that it could be that users would pay for a heavy transport bypass, so trucks could avoid Portrush Road, for example. "The truth is nobody's going to win votes talking up toll roads, I don't see either side embracing the toll road concept," he said. But if every other state has had to go down the toll road avenue, are we arrogant enough to say we won't consider it? "What we're looking at is ways in which it can be funded through some mechanism which involves a contribution from industry," he said. The Federal Government advisory group Infrastructure Australia has positively reviewed the Northern Connector project, a road and rail plan to link the Northern and Port River expressways, but insisted tolls be considered to support the business plan for construction. Federal Assistant Infrastructure Minister Jamie Briggs said the Coalition was not opposed to state governments using tolls on roads they funded, and said he looked forward to the Productivity Commission's report. Mr Weatherill yesterday also called on the Federal Government to back away from plans to upgrade the Darlington Interchange and instead back the Torrens to Torrens upgrade of South Rd around the Port Rd intersection, arguing engineering plans were far further advanced.