The freight services industry is welcoming an independent inquiry into how efficient transport services are for international freight, saying there's room for improvement.
The Productivity Commission says international trade is critically important to New Zealand, as a nation of exporters located a long way from major world markets.
It will look at ways to ensure the country's infrastructure and regulations are effective at managing overseas freight.
New Zealand has 13 ports across the country and Port of Tauranga chairman John Parker says that's too many.
He says New South Wales has one port for a population that's about the same size as New Zealand.
Mr Parker says he's not suggesting ports should vanish, but there should probably only be one port in the north and one in the south to service the major part of export containers.
The New Zealand Shippers Council says some ports need to prepare to accommodate bigger ships.
Chairman Greg Steed says New Zealand is projected to have tremendous growth in terms of its agricultural exports in the next five to 10 years.
While he does not advocate port closures, Mr Steed says there may be room for some to change how they operate - like specialising in cargo outside of containers.
Export New Zealand executive director Catherine Beard says some shipping lines are concerned that if the number of ports drops, the market will be less competitive.
Economist John Small of Auckland says the lack of an overarching strategy which ties together rail, sea, road and air freight needs to be addressed.
He says it's been piecemeal with different governments having different focus.
Mr Small says a commission needs to look at the full picture.
But a senior associate at Victoria University's Institute of Policy Studies is less optimistic about the inquiry.
Geoff Bertram says he's concerned this is a step towards trying to privatise the freight industry.
The commission is due to report back by 1 April next year.