Auckland Transport must commit to a major roading component of the $1.4 billion Eastern Busway, say National's Pakuranga MP Simeon Brown and Botany candidate Christopher Luxon.
The pair said the Reeves Rd flyover is a critical piece of infrastructure for east Auckland, but are concerned it is being ditched from the busway project.
"The east Auckland community has been promised a Reeves Rd flyover and expects a Reeves Rd flyover to be delivered," they said in a letter to AT chief executive Shane Ellison.
They are concerned because AT is calling for expressions of interest to build the next stage of the busway linking Panmure, Pakuranga and Botany, but says "the Reeves Rd flyover is no longer a required component of the project".
Luxon and Brown said the new scope had changed to a grade separated busway/Ti Rakau Drive and Reeves Rd intersection and improved access to reduce traffic around Pakuranga town centre.
"The documents allow whoever wins the busway contract to design something quite different," Luxon said.
The flyover has been planned as a new road bridge linking Pakuranga Rd to Waipuna Bridge above Reeves Rd and across Ti Rakau Drive.
The 7km busway is similar to the Northern Busway with separated lanes for buses and stations at Pakuranga and Botany, as well as walking and cycling connections. It will serve the fast-growing eastern suburbs, which have a population of 130,000 - about the same as Dunedin.
AT has previously said it will reduce traffic on Pakuranga Rd and Ti Rakau Drive bordering the town centre by 40 per cent at peak hours and become a potential visual landmark and gateway to Pakuranga.
Two years ago, the flyover and a new station at Pakuranga was priced at $270m and listed by Auckland Council as a project to receive funding from the regional petrol tax of 11.5 cents a litre.
The flyover has had an on-again, off-again history. In 2015, AT announced it would defer the project to put the savings towards the busway, sparking huge outrage. The transport body backed down.
On Friday, AT announced it was seeking a "registration of interest" for stages two, three and four of the busway. Construction is under way on stage one from Panmure to Pakuranga.
Mayor Phil Goff said the next stages - construction is set down to start in 2022 once a design, engineering and construction consortium is formed and consent is granted - will be one of the biggest projects in Auckland.
Goff said they represented a spend of $700m with huge benefits for rapid public transport, cycling and walking as well as easing traffic congestion.
The project is due to for completion in 2025, a year after the $4.4 billion City Rail Link is due for completion.
An AT spokesman said the flyover in its current form remains within the design, but AT would consider new innovative "grade separated" options that provides the same or improved results in a way that may reduce community impacts.
He said it is best practice to enable innovation as part of an Alliance "registration of interest" process to seek the best value for money while achieving the same community and transport objectives.
"This point has been made clear in previous discussions with Mr Brown and no objections were made at the time. Any changes or alternative options to the current design plans for stages 2, 3 and 4 of the project will go out for community consultation in advance of the consenting process," the spokesman said.
He said the Reeves Rd Flyover remains an integral part of the Eastern Busway and meant to reduce congestion around the town centre by at least 40 per cent, improve safety and enable frequency and reliability of the new busway while also offering a critical new connection and significantly improved access for traffic between Pakuranga Rd and Waipuna Bridge.
Auckland Transport and the future alliance are absolutely committed to these outcomes for the people of East Auckland, the spokesman said.