The Labour Party says the proposed light rail network and the City Rail Link could together resolve Auckland's ever-growing traffic woes.
Auckland Council's transport agency said it might decide within months whether it favoured replacing buses with light rail on central arterial routes.
Labour's Auckland Issues spokesperson, Phil Goff, said the City Rail Link would only really benefit people living out west and in the south.
"We've got to look at alternatives, we've looked as bus ways but those bus ways are now approaching capacity."
Mr Goff said a light rail network could be the answer, as it could carry three times as many people and at faster speeds.
But he said the cost and who should bear it needed to be worked out.
Auckland Council's transport agency was investigating whether it favoured replacing buses with light rail on major central arterial roads.