Critics turn spotlight on Transit's cost 'blowouts'

Transit New Zealand faces a complaint to the Auditor-General and criticism from the Auckland Chamber of Commerce for alleged roading cost blowouts.

Waiwera resident and MMP activist Dr Hans Grueber has asked Auditor-General Kevin Brady to investigate the planned motorway extension to Puhoi, claiming to have evidence that Transit "is deliberately misspending taxpayers' money" to justify a need to charge tolls on the road.

"There has between 2003 and 2004 been a cost explosion ... that is hard to explain," he told Mr Brady in a covering letter to affidavit evidence, yet to be released publicly.

His letter, sent last week, was overtaken on Monday by a disclosure by Transit chief executive Rick van Barneveld to the Environment Court that the estimated cost of the 7.5km road had jumped $65 million to $365 million since August.

Mr van Barneveld said the latest figure included an "escalation" provision not included in the earlier figure, which pre-dated a construction agreement allowing the project to begin last week.

Chamber of Commerce CEO Michael Barnett said this disclosure was "a drop in the ocean" against what he claimed were cost increases of more than $400 million on Auckland roading projects this year.

Mr Barnett said the costs were compounded by delays to projects from a lack of Government commitment, which had resulted in years of under-investment by a roading industry which was now having to ask Transit to slow its tendering processing.

Dr Grueber said he obtained his affidavit from an industry source who claimed Transit was disguising costs on the Puhoi project to substantiate a need for tolls.

A sector manager at Mr Brady's office, Robert Cox, confirmed receiving Dr Grueber's letter with the affidavit and said they raised issues warranting consideration of whether to start a formal investigation.

But a decision would have to wait until after Christmas.

Transit capital projects general manager Colin Crampton would not comment on the claims, but stood by the latest Puhoi estimate as the final figure cleared by his board.