A commuter rail service between Rangiora and Christchurch is under consideration.
The regional council Environment Canterbury is looking at the idea as a way of easing traffic congestion.
The population north of Christchurch has grown so rapidly since the damaging earthquakes that commuter traffic has slowed to a crawl and trips can take up to three times longer than they used to.
A proposed study would investigate using old diesel-powered commuter trains from Auckland that have just been replaced by electric trains.
There's also the possibility of using KiwiRail's Picton-to-Christchurch passenger trains, which at present sit idle apart from the summer season.
The trains would use the existing main trunk line and link Rangiora's station with the one in the city suburb of Addington.
Waimakariri mayor David Ayers said a service to take pressure off the roads during rush-hour can't come soon enough.
"The queuing is considerable, down to a slow crawl. About three weeks ago I went to a meeting in Addington and it took me an hour and forty minutes. When I came home it took me thirty-five."
Labour's Waimakariri MP Clayton Cosgrove says the passenger service is a no-brainer, but says it needs to be done as part of an integrated transport plan for the whole city.
Extra buses would also be needed to take passengers from train stations to their final destinations, he said.
Environment Canterbury commissioners will vote on Thursday on whether to go ahead with the study.