Labour is promising $100 million towards fixing Greater Christchurch's traffic woes.

Andrew Little has just released the details of a new policy - which would include funding a commuter rail service from Rolleston.

The money will come from the National Land Transport Fund.

The Labour Leader said Christchurch commuters lag behind those in Auckland or Wellington - with only three percent taking public transport.

"This is about reflecting the fact that there's been a massive growth in the population around Rolleston, triple since 2006 I think, growing congestion on the Southern motorway, 5% a year now, and hust the need for better public transport around Christchurch."

In addition to rail, Labour would fund better infrastructure for buses and bus feeder services.