Proposals to fix Wellington's growing traffic congestion are being accused of having little regard for the environment.

Let's Get Wellington Moving has released four new transport scenarios costing as much as $2.3 billion.

They include duplicating the Mount Victoria and Terrace tunnels and a fourth Southbound lane between Ngauranga and Aotea.

Documents concede the proposals only have a minor impact on reducing green house gas emissions but that the project will make taking public transport easier.

Central City Councillor Iona Pannett said that's not good enough.

"Essentially they're saying that greenhouse gas emissions will be cut through other mechanisms. This plan, this very expensive plan, will do nothing or have no impact at all on emissions."

The claims have been refuted by local transport experts.

Let's Get Wellington Moving governance group member Chris Calvi-Freeman said the new road and tunnels will make taking public transport easier.

"The roading proposals are designed to clear the way for through traffic to be separated from city traffic, and for city traffic to clear the way for more public transport, walking and cycling."

They have also been criticised by the Transport Minister, who said new proposals to fix Wellington's traffic problem are lacking ambition.

Phil Twyford says he's committed to working with Wellington but seems unimpressed with its road-focused approach.

"We have a Government that is committed to building up the role of public transport, and investing in modern rapid transit in our cities to make them work better, to reduce congestion and give people a much better alternative to being stuck in traffic."