Brisbane City Council's plan to "recycle" about $1 billion in capital to bring forward two big Brisbane road projects has won the praise of one of Queensland's senior infrastructure bodies.
Brisbane City Council has an "in principle" deal with Queensland Motorways to lease the toll operations for the $1.5 billion Legacy Way toll tunnel and the $320 million Go Between Bridge for 50 years.
In return for allowing Queensland Motorways to receive the majority of the toll revenue for 50 years, when Legacy Way opens in early 2015, the council will receive between $1.08 billion and $1.58 billion by 2020.
Council will use $650 million of the money to widen Kingsford Smith Drive to six lanes by 2019 and about $150 million to widen Wynnum Road near Shafston College in 2016.
Roger Black, executive director of Infrastructure Association Queensland, said it was a good move.
"The best value for infrastructure is achieved by recycling capital," Mr Black said.
"And the IAQ would probably encourage more projects like this where there is the opportunity to recycle capital and use that on other projects, because we live in an environment which is capital constrained."
Mr Black argued the consortiums had "no control" over traffic forecasts put together during a period of "deal frenzy" between 2006 and 2008.
"I think those transactions were done in a time when there was a real deal frenzy going on, and people were wanting to win deals ahead of anything sensible," he said.
Brisbane's first toll tunnel, the Clem7, went into liquidation in April 2011, while the city's second toll tunnel, the Airport Link, went broke in February 2013.
Mr Black said the way the council had designed Legacy Way had ruled out the construction risk.
The traffic risk is based on two sets of traffic estimates; one prepared by Queensland Motorways and a second, slightly higher set of figures provided by the council.
Under Queensland Motorways estimates, Legacy Way traffic would increase from 16,700 per day when opened in July 2015 to at least 24,500 a day.
However on the council's own projections, traffic would increase from 24,000 per day and increase to 46,100 per day.
Mr Black said the council's estimation sounded like a "sensible number".
"On the face of it those numbers sound a lot more sensible than the numbers that were used on both the Clem7 and the Airport Link," he said.
He said the 50-year lease was appropriate for a large infrastructure project.
"Most infrastructure would need some where beyond 30 years to make it viable," he said.
State and federal governments need to give the council-Queensland Motorways deal the final tick of approval and the full council must approve the decision on July 30.