A report from the Waikato Chamber of Commerce claims the Auckland to Hamilton rail route is more expensive and releases more carbon per person than driving

The chamber says occupancy rates are at only 23 percent during Te Huia's weekday service.

It also says the service reduces congestion Northbound traffic on State Highway one by less than one percent.

Chamber chief executive Don Good says the Waikato Regional Council's introducing significant upgrades to the service this year to attract more patronage.

But he says given Te Huia's 100-million dollar price tag, there needs to be real accountability from those behind its implementation.