Greater transparency in the infrastructure sector would result in better projects and a better public response to them, according to a report by the Infrastructure Commission.
Massey University research, commissioned by the group, assessed the accessibility of key documents for 27 large projects across central and local government, ranging in cost from $50 million to well over $1 billion.
The study assessed projects with an overall rating out of nine for accessibility to their documents, with 63 percent of projects scoring only three to five.
The highest-scoring projects were run by an independent board, rather than by a government agency or council, and nearly all were worth more than $500 million.
Te Waihanga New Zealand Infrastructure Commission chief executive Ross Copland said despite New Zealand's high ranking on the international Corruption Perceptions Index, information on major projects was not always easy to access.
"New Zealand does not currently have public accountability standards for proactive disclosure for large, public infrastructure projects, so we're seeing inconsistent performance in how New Zealanders are being kept informed," he said.
"The research showed that around half of all the Business Case and Assurance Case documents in these big, public projects were not accessible, and that reviews were not accessible for completed projects."
The research revealed some large projects were proactive in making disclosures, which was positive, Copland said.
"However, it also shows significant opportunities to improve transparency across our major projects, including increasing the expectations for proactive disclosure."
About 16 percent of New Zealanders' household budgets was spent on infrastructure services and people deserved to know what they were funding, Copland said.