National is pledging $4 billion for transport projects in Wellington in a bid to "end" congestion woes, including building new tunnels and routes.
"This region is choked by congestion," National leader Judith Collins said. "Wellington has the worst traffic in Australasia for a city under one million people."
Ms Collins said National's election promise was to fast-track a second Mt Victoria Tunnel and create a second Terrace Tunnel, adding levels to "unblock" the Basin Reserve.
National is also promising to create rapid transport from the airport, pull State Highway 1 underground around Te Aro and build a new highway from Seaview in Lower Hutt to SH1 north of Wellington.
It also wanted to create a new route between Petone to Grenada, costing $900 million.
The second Terrace Tunnel was costed by National at $400 million of new funding and expected to begin in 2029.
The party also wants to upgrade the metro network to make new rail lines between Wellington, Masterton and Palmerston North.
Ms Collins said National would, if needed, pass new laws to speed up the creation of the second Mt Victoria Tunnel, which would cost $700 million.
It would have a separated walking and cycling lanes.
The undergrounding of SH1 through Te Aro would cost $1.1b of new funding and begin in 2029.