This afternoon Let's Get Wellington Moving (LGWM) will officially announce four options to overhaul the city's transport network with a second Mt Victoria tunnel and mass rapid transit.
Last month the Herald was given the details of the packages to go out for public feedback.
At that stage, the options were yet to be signed off and could have changed between then and now, although sources believed significant changes were unlikely.
The first option has light rail going from the railway station to Island Bay, a bus priority system to the airport and eastern suburbs, and grade separation at the Basin Reserve.
It's understood the grade separation involves the extension of the Arras tunnel.
The first option also has a new tunnel through Mt Victoria for traffic and buses, while the existing tunnel will be converted for walking and cycling.
The second option is essentially the same but switches light rail to Island Bay for bus rapid transit instead.
Option three has light rail to Island Bay and bus priority to the east, grade separation at the Basin, but a new tunnel for walking and cycling, while the existing Mt Victoria tunnel remains.
The fourth option is the same as the third but with no grade separation at the Basin.
Wellington City and regional councillors have been told not to publicly comment on the proposals until the official announcement later today.
LGWM governance reference group chairman Daran Ponter said the four options have been refined from a long list of proposals.
"The four options deal with many of the issues that Wellingtonians have been quite rightly concerned to see Let's Get Wellington Moving deliver on for quite a long time. They are in relation to mass rapid transit to the east and south, tunnelling through Mt Victoria, and better resolution of congestion in and around the Basin Reserve."
Ponter said a second tunnel and mass rapid transit had always been the "bigger rocks" within the LGWM project.
But he said they have also become the "butt of jokes" in relation to criticism the project has been moving too slowly.
Ponter said people had been asking: "Where is this mythical mass rapid transit system?"
"These options that are released on Monday afternoon will start to give some shape to what they might look like in a few years' time," Ponter said.
"It's a good feeling to finally be able to put something in front of the public and move on to a conversation about the substance and not just the process."
But National list MP Nicola Willis said it would be hard to take the announcement seriously, considering the endless delays to Let's Get Wellington Moving.
"My faith has been completely eroded, are we really any further ahead? Wellingtonians have been debating options and packages and doing consultation and working groups on options for literally years. This just feels like we're back to square one with a debate on different options."
However, Willis said she was pleased the four packages revealed by the Herald all had an option to expand the Mt Victoria tunnel.
"What's been clear from Wellingtonians is that any investment in our transport infrastructure needs to make it easier to get around the city. The reality is many of us get around by cars and we can expect that to continue to be the case.
"What we need is great options for public transport, for walking and cycling, and a reduction in car congestion."
Green Party transport spokeswoman Julie Anne Genter, who is also a list MP based in Wellington, said the options indicated a move in a much better direction and away from a "legacy of motorway planning".
She said people wanted good, effective, affordable public transport options.
"They want inner-city living, they want safer walking and cycling and pedestrianisation. It feels like the last Let's Get Wellington Moving process was hanging on to old ways at looking at transport and this has really pivoted to something that's actually going to solve the problems that are relevant in the 21st century."
But Genter said she didn't understand why it has taken LGWM so long to produce something useful.
She said a dedicated walking and cycling tunnel was included in the party's transport policy for Wellington by using the existing pilot tunnel, which runs parallel to the current Mt Victoria tunnel.
"This would be quite inexpensive, relatively, and quicker to deliver than repurposing the Mt Victoria tunnel that would come quite late in the piece."
Genter said she supported light rail to Island Bay and Newtown being the first priority in mass rapid transit for the city.