After a new designation was confirmed in March, landowners Green McCahill Holdings and Weiti Developments near the route lodged appeals relating to access to their housing developments.
But last month they reached an agreement with Auckland Transport - the private firms will build a roundabout and part of the southbound on-ramps to the 7km road next month even though the project hasn't even been funded.
Auckland Chamber of Commerce chief executive Michael Barnett said in a Herald opinion piece in June that Penlink's cost was "modest" compared with the billions of dollars of recent larger projects. Its benefit-cost ratio of 2.9 also gave it a rating higher than several of NZTA's Roads of National Significance.
With council dragging its feet on funding, Barnett said the pre-conditions are in place for a farsighted local private-sector investor to add Penlink to its portfolio.
"Clearly, the traditional approach of relying on council hasn't worked. If the project is to be speeded up, a new approach is required."
In its business case, the highway was touted as a "very strong candidate" for a public private partnership with a toll of up to $3 a trip.
Hibiscus and Bays local board chairwoman Julia Parfitt said Whangaparaoa residents have always been happy with paying a toll - just as long as it got built to ease pressure on the sole congested road on and off the peninsula.
It would also help unlock the potential of Silverdale as an economic hub for the north and help connections to intensive housing areas like Dairy Flat.
"Silverdale was meant to be an employment centre but the massive congestion either side is a huge chock to that development. [Penlink] is desperately needed now. We're ready. We're just waiting for Auckland Transport."
Auckland Transport spokesman Mark Hannan said they did not have construction funding but were "regularly reviewing the priority" for Penlink.