Proponents of an underground rail line through downtown Auckland hope the experience of a project in London will bolster their case for funding.
Economic benefits that Auckland Council claims will flow from the $2.4 billion project have been questioned by the Government.
But a $30 billion express rail link across London received government backing on the basis of wider benefits.
Auckland's case was assembled by PricewaterhouseCoopers.
PWC director Chris Money says narrower criteria in New Zealand favour simpler roading projects rather than complex urban schemes.
New research has been commissioned by the Transport Agency on how to measure the wider economic benefits of major projects.
More on this can be heard on Insight on Sunday.