This is complemented by a bus priority system through the city and to the airport and the eastern suburbs, including Miramar.
A new tunnel through Mt Victoria will be built, which will run diagonally roughly from the Basin Reserve to the Badminton Centre on the Hataitai side. The tunnel will have two lanes for traffic and two for bus priority.
The existing Mt Victoria tunnel will be converted for walking and cycling.
The area around the Basin Reserve will be fully grade separated, so traffic going in different directions can move more freely.
The second option is essentially the same: bus priority to the eastern suburbs, a diagonal tunnel through Mt Victoria, and the existing tunnel will be converted to active modes.
It also keeps grade separation at the Basin Reserve, but it switches light rail to Island Bay for bus rapid transit - essentially high-frequency, high capacity buses running down a dedicated route.
Option three also has light rail to Island Bay, and bus priority to Miramar and Island Bay.
A new tunnel will be dug through Mt Victoria for walking and cycling, which will mean traffic continues to use the existing tunnel.
Option four has light rail again heading to Island Bay, bus priority again heading to the east to Miramar and the airport, and includes the active mode tunnel through Mt Victoria.
The key difference is that it does not grade separate the Basin Reserve.
All four options will be put to Wellingtonians to have their say before final decisions are made.
Dunlop said here was "considerable interest in the four options"..
"The options will focus on a mix of new mass rapid transit – either light rail or bus rapid transit – improvements at the Basin Reserve, and an extra Mt Victoria Tunnel, and the urban development this can enable," Dunlop said.
"These are key to supporting our growing population, with 50,000 to 80,000 more people expected in Wellington City over the next 30 years."
Dunlop acknowledged the focus of the programme had shifted from the city to airport route to the city to Island Bay route. A key question is whether one of the options will be presented as the prefferred option or the option that best matches the programme priorities.
"We're looking at major changes to two public transport routes – a southern suburbs route from the Wellington Railway Station to Island Bay, with big potential for more housing. And an eastern suburbs route through Mt Victoria – an important connection but with less potential for more housing," he said.
"Public engagement is an important opportunity for the community and stakeholders to help shape and develop a preferred transport option that moves more people with fewer vehicles and supports Wellington's growth.
"From early November we strongly encourage all Wellingtonians to have their say by visiting www.lgwm.nz," he said.
Let's Get Wellington Moving was first announced in 2019 as a $6.4 billion agreement between central Government, which would pick up 60 per cent of the costs, and Wellington City and Greater Wellington regional councils, which would pick up the remaining 40 per cent.