Mr Brownlee has considered a report presented to him in October last year by South Island supporters of the remote 108km road and is now waiting for the ministries of economic development and tourism to give him more information.
Mr Brownlee told the Otago Daily Times yesterday that while he personally supported the project, the Government was "not committed either way".
However, he believed the project - first mooted over a century ago - was being more actively considered than at any other time.
"I've been saying things like we are at the early stages of consideration. That sounds a bit nuts because it has been around for so long . . . But I referred it to the ministries . . . to consider and put into context of what the value might be. It has not progressed any further at this point.
"The Government has not said `yes' or `no' . . . We have to ensure there is enough support before it goes further. That is what I am doing, trying to grow that support."
Mr Brownlee said support was also needed from local authorities, which grant resource consents, and a private funding partner could also be needed.
The estimated $200 million-$300 million cost of building the road, contained in an Octa Associates report presented to Mr Brownlee by Scenic Group director Earl Hagaman last year, was probably "on the light side", he said.
There were economic constraints but the southern region had enormous tourism potential, Mr Brownlee said.
There would still be "tens of thousands of kilometres with no access except for helicopters."
The Haast-Hollyford road route is within Department of Conservation estate.
"Being conservation estate, all processes have to be sketched out and put in front of us. It shouldn't be a deterrent. Conservation land is owned by all New Zealanders. As we know, not every piece of land has high value," Mr Brownlee said.
Mr Hagaman said yesterday the route would be the "eighth wonder of the world" and save significant travel time and petrol consumption costs for people touring the West Coast to Milford Sound.
It would also provide commercial and tourism opportunities to West Coast towns and open up a largely unknown, beautiful area to more people.
Mr Hagaman expected some opposition from recreationalists.
"But I would tell the greenies if they feel that strongly, they should go live in a cave."
Mr Hagaman did not know whether private investors were willing to discuss a partnership with the Government to build the road.
"I just don't have a feel for that at the moment. It is a lot of money. But the Government is borrowing $250 million every week to support itself. So it is not a back-breaking situation if they can get their surplus costs cut back," he said.
Octa Associates director David McLernon said yesterday he had studied previous reports and other suggested Haast-Hollyford routes.
The next stage of the project would be to complete a pre-feasibility study that, among other things, would more clearly establish the route and costs, gather more engineering details and analyse the costs and benefits of imposing a road toll.
That would need about $150,000 in funding and take about four to six months.
Mr McLernon said building the Haast-Hollyford road should be relatively simple to engineer compared with the Arthurs Pass viaduct project.
The proposed coastal route would not get as much rain as an inland route.
It only reached 150m above sea level and did not cross the alpine fault.
