Wellington Regional Council and KiwiRail say they have no plans to provide wi-fi on trains after the Green Party called for the investment to encourage the use of public transport.
Green Party transport spokesman Gareth Hughes believed it would cost less than $1 million a year to provide free wi-fi on all 346 train carriages and 80 to 100 stations in Wellington and Auckland, making that a "no-brainer".
Steve Simms, executive director of Auckland wi-fi provider Tomizone, said the cost estimate was about right.
A poll of 200 commuters found more than 75 per cent of Wellingtonians and more than 90 per cent of Aucklanders were "highly supportive of the idea", Hughes said.
The investment would mean commuters with smartphones or laptops would be able to check the forecast arrival times of trains and buses free-of-charge while travelling by accessing the real-time passenger information system on MetLink's website, as well as use the service for work or entertainment.
"Any savings on deferred costs of new motorways planned by the National Government would pay for these public transport improvements many times over," Hughes said.
KiwiRail spokeswoman Cathie Bell said the carriages were council-owned and it had no plans for free wi-fi at this stage. Wellington Regional Council economic wellbeing committee chairman Peter Glensor said he viewed wi-fi as a "nice to have".
The council's focus was on upgrading the rail network and continuing to roll out the real-time passenger information system. After that the next priority would probably be integrated ticketing, he said.
Once real-time information was available for trains, passengers with smartphones would be able to check that by logging on to the MetLink site using their own 3G connection, Glensor said.
He was not convinced that cost should instead be met by ratepayers through free wi-fi.
Tomizone won a tender to provide a free wi-fi internet service for the 200,000 passengers using Sydney's ferries and may bid for a tender let by New South Wales train operator Rail Corp. Australian surveys had shown wi-fi made a profound difference to public transport users, Simms said.